#include <bits/stdc++.h>

using namespace std;

int main() {
#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
//	freopen("output.txt", "w", stdout);
#endif
	
	int n, m;
	cin >> n >> m;
	vector<int> cnt(m + 2);
	for (int i = 0; i < n; ++i) {
		int l, r;
		cin >> l >> r;
		++cnt[l];
		--cnt[r + 1];
	}
	for (int i = 1; i <= m; ++i)
		cnt[i] += cnt[i - 1];
	
	vector<int> ans;
	for (int i = 1; i <= m; ++i) {
		if (cnt[i] == 0)
			ans.push_back(i);
	}
	
	cout << ans.size() << endl;
	for (auto it : ans) cout << it << " ";
	cout << endl;
	
	return 0;
}

n, m = map(int, input().split())
seg = [list(map(int, input().split())) for i in range(n)]
def bad(x):
	for i in range(n):
		if (seg[i][0] <= x and x <= seg[i][1]): return False
	return True
ans = list(filter(bad, [i for i in range(1, m + 1)]))
print(len(ans))
print(' '.join([str(x) for x in ans]))

#include <bits/stdc++.h>

using namespace std;

int main() {
#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
//	freopen("output.txt", "w", stdout);
#endif
	
	int n;
	string s, t;
	cin >> n >> s >> t;
	
	vector<int> ans;
	for (int i = 0; i < n; ++i) {
		if (s[i] == t[i]) continue;
		int pos = -1;
		for (int j = i + 1; j < n; ++j) {
			if (s[j] == t[i]) {
			        pos = j;
			        break;
			}
		}
		if (pos == -1) {
			cout << -1 << endl;
			return 0;
		}
		for (int j = pos - 1; j >= i; --j) {
			swap(s[j], s[j + 1]);
			ans.push_back(j);
		}
	}
	
	assert(s == t);
	
	cout << ans.size() << endl;
	for (auto it : ans) cout << it + 1 << " ";
	cout << endl;
	
	return 0;
}

#include <bits/stdc++.h>

using namespace std;

int main() {
#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
//	freopen("output.txt", "w", stdout);
#endif
	
	int n, m;
	cin >> n >> m;
	vector<pair<int, int>> a(n);
	long long sum = 0;
	for (int i = 0; i < n; ++i) {
		cin >> a[i].first >> a[i].second;
		sum += a[i].first;
	}
	
	sort(a.begin(), a.end(), [&](pair<int, int> a, pair<int, int> b) { return a.first - a.second > b.first - b.second; });
	
	for (int i = 0; i < n; ++i) {
		if (sum <= m) {
			cout << i << endl;
			return 0;
		}
		sum -= a[i].first - a[i].second;
	}
	
	if (sum <= m)
		cout << n << endl;
	else
		cout << -1 << endl;
	
	return 0;
}

def step(cur, x):
    if(cur - x > 0):
        return cur - x
    else:
        return cur + x



n, k, s = map(int, input().split())
cur = 1

if(k > s or k * (n - 1) < s):
    print('NO')
else:
    print('YES')
    while(k > 0):
        l = min(n - 1, s - (k - 1))
        cur = step(cur, l)
        print(cur, end = ' ')
        s -= l
        k -= 1

#include <bits/stdc++.h>

using namespace std;

#define forn(i, n) for (int i = 0; i < int(n); i++)

const int dx[] = {1, 0, -1,  0};
const int dy[] = {0, 1,  0, -1};
const int N = 1001;

int n, m;
vector<string> f;
int d[N][N][4];
int r[N][N], a[N][N], b[N][N];

int getd(int i, int j, int k) {
    int dxk = dx[k];
    int dyk = dy[k];
    int result = 0;
    while (i >= 0 && i < n && j >= 0 && j < m && f[i][j] == '*')
        result++, i += dxk, j += dyk;
    return result;
}

int main() {
    cin >> n >> m;
    f = vector<string>(n);
    forn(i, n)
        cin >> f[i];
    
    memset(d, -1, sizeof(d));
    int result = 0;
    for (int i = 1; i + 1 < n; i++)
        for (int j = 1; j + 1 < m; j++)
            if (f[i][j] == '*') {
                bool around = true;
                forn(k, 4)
                    around = around && (f[i + dx[k]][j + dy[k]] == '*');
                if (around) {
                    r[i][j] = INT_MAX;
                    forn(k, 4)
                        r[i][j] = min(r[i][j], getd(i, j, k) - 1);
                    result++;
                    a[i][j - r[i][j]] = max(a[i][j - r[i][j]], 2 * r[i][j] + 1);
                    b[i - r[i][j]][j] = max(b[i - r[i][j]][j], 2 * r[i][j] + 1);
                }
            }

    vector<string> g(n, string(m, '.'));
    forn(i, n) {
        int v = 0;
        forn(j, m) {
            v = max(v - 1, a[i][j]);
            if (v > 0)
                g[i][j] = '*';
        }
    }
    forn(j, m) {
        int v = 0;
        forn(i, n) {
            v = max(v - 1, b[i][j]);
            if (v > 0)
                g[i][j] = '*';
        }
    }
    
    if (f == g) {
        cout << result << endl;
        forn(i, n)
            forn(j, m)
                if (r[i][j] > 0)
                    cout << i + 1 << " " << j + 1 << " " << r[i][j] << endl;
    } else
        cout << -1 << endl;
}

#include <bits/stdc++.h>

using namespace std;

int n, m;
vector<string> s;

vector<string> draw(const vector<pair<pair<int, int>, int>> &r) {
	vector<string> f(n, string(m, '.'));
	vector<vector<int>> h(n, vector<int>(m));
	vector<vector<int>> v(n, vector<int>(m));
	for (auto it : r) {
		int x = it.first.first;
		int y = it.first.second;
		int len = it.second;
		++v[x - len][y];
		if (x + len + 1 < n)
			--v[x + len + 1][y];
		++h[x][y - len];
		if (y + len + 1 < m)
			--h[x][y + len + 1];	
	}
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < m; ++j) {
			if (i > 0) v[i][j] += v[i - 1][j];
			if (j > 0) h[i][j] += h[i][j - 1];
			if (v[i][j] > 0 || h[i][j] > 0)
				f[i][j] = '*';
		}
	}
	return f;
}

int main() {
#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
//	freopen("output.txt", "w", stdout);
#endif
	
	cin >> n >> m;
	s = vector<string>(n);
	for (int i = 0; i < n; ++i) {
		cin >> s[i];
	}
	
	vector<vector<int>> l(n, vector<int>(m));
	vector<vector<int>> r(n, vector<int>(m));
	vector<vector<int>> u(n, vector<int>(m));
	vector<vector<int>> d(n, vector<int>(m));
	
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < m; ++j) {
			if (i > 0) {
				if (s[i][j] != '.')
					u[i][j] = u[i - 1][j] + 1;
			} else {
				u[i][j] = s[i][j] != '.';
			}
			if (j > 0) {
				if (s[i][j] != '.')
					l[i][j] = l[i][j - 1] + 1;
			} else {
				l[i][j] = s[i][j] != '.';
			}
		}
	}
	for (int i = n - 1; i >= 0; --i) {
		for (int j = m - 1; j >= 0; --j) {
			if (i < n - 1) {
				if (s[i][j] != '.')
					d[i][j] = d[i + 1][j] + 1;
			} else {
				d[i][j] = s[i][j] != '.';
			}
			if (j < m - 1) {
				if (s[i][j] != '.')
					r[i][j] = r[i][j + 1] + 1;
			} else {
				r[i][j] = s[i][j] != '.';
			}
		}
	}
	
	vector<pair<pair<int, int>, int>> ans;
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < m; ++j) {
			if (s[i][j] == '*') {
				int len = min(min(u[i][j], l[i][j]), min(d[i][j], r[i][j])) - 1;
				if (len != 0) {
					ans.push_back(make_pair(make_pair(i, j), len));
				}
			}
		}
	}
	
	if (draw(ans) != s) {
		cout << -1 << endl;
	} else {
		cout << ans.size() << endl;
		for (auto it : ans) {
			cout << it.first.first + 1 << " " << it.first.second + 1 << " " << it.second << endl; 
		}
	}
	
	return 0;
}

#include <bits/stdc++.h>

using namespace std;

const int N = 203;
const int MOD = 1e9 + 7;

int n, ssz;
string s;
int len[N][2];
int dp[N][N][N][2];

int calc(const string &t) {
	int tsz = t.size();
	for (int i = tsz; i > 0; --i) {
		if (s.substr(0, i) == t.substr(tsz - i, i))
			return i;
	}
	return 0;
}

void add(int &a, int b) {
	a += b;
	if (a >= MOD)
		a -= MOD;
	if (a < 0)
		a += MOD;
}

int main() {
#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
//	freopen("output.txt", "w", stdout);
#endif
	
	cin >> n >> s;
	ssz = s.size();
	
	if (s[0] == '(')
		len[0][0] = 1;
	else
		len[0][1] = 1;
	
	string pref;
	for (int i = 0; i < ssz; ++i) {
		pref += s[i];
		pref += '(';
		len[i + 1][0] = calc(pref);
		pref.pop_back();
		pref += ')';
		len[i + 1][1] = calc(pref);
		pref.pop_back();
	}
	
	dp[0][0][0][0] = 1;
	for (int i = 0; i < 2 * n; ++i) {
		for (int j = 0; j <= n; ++j) {
			for (int pos = 0; pos <= ssz; ++pos) {
				for (int f = 0; f < 2; ++f) {
					if (dp[i][j][pos][f] == 0) continue;
					if (j + 1 <= n)
						add(dp[i + 1][j + 1][len[pos][0]][f | (len[pos][0] == ssz)], dp[i][j][pos][f]);
					if (j > 0)
						add(dp[i + 1][j - 1][len[pos][1]][f | (len[pos][1] == ssz)], dp[i][j][pos][f]);
				}
			}
		}
	}
	
	int ans = 0;
	for (int i = 0; i <= ssz; ++i)
		add(ans, dp[2 * n][0][i][1]);
		
	cout << ans << endl;
	
	return 0;
}