#include <bits/stdc++.h>

using namespace std;

int main() {
#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
//	freopen("output.txt", "w", stdout);
#endif
	
	int h1, m1;
	scanf("%d:%d", &h1, &m1);
	int h2, m2;
	scanf("%d:%d", &h2, &m2);
	int t1 = h1 * 60 + m1;
	int t2 = h2 * 60 + m2;
	int t3 = (t1 + t2) / 2;
	printf("%02d:%02d\n", t3 / 60, t3 % 60);
	
	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, k;
	cin >> n >> k;
	vector<int> cnt(k);
	for (int i = 0; i < n; ++i) {
		int x;
		cin >> x;
		++cnt[x % k];
	}
	int ans = cnt[0] / 2;
	if (k % 2 == 0) ans += cnt[k / 2] / 2;
	for (int i = 1; i < (k + 1) / 2; ++i) {
		int j = k - i;
		ans += min(cnt[i], cnt[j]);
	}
	
	cout << ans * 2 << 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;
	cin >> n;
	vector<int> a(n);
	for (int i = 0; i < n; ++i) {
		cin >> a[i];
	}
	sort(a.begin(), a.end());
	int ans = 0;
	int j = 0;
	for (int i = 0; i < n; ++i) {
		while (j < n && a[j] - a[i] <= 5) {
			++j;
			ans = max(ans, j - i);
		}
	}
	
	cout << ans << endl;
	
	return 0;
}

#include<bits/stdc++.h>

using namespace std;

#define x first
#define y second

const int N = 200043;

void norm(pair<int, int>& p)
{
	if(p.x < 0)
	{
		p.x *= -1;
		p.y *= -1;
	}
	else if (p.x == 0 && p.y < 0)
	{
		p.y *= -1;
	}
	int d = __gcd(abs(p.x), abs(p.y));
	p.x /= d;
	p.y /= d;
}

map<pair<int, int>, int> m;

int a[N];
int b[N];
int n;

int main()
{
	scanf("%d", &n);
	for(int i = 0; i < n; i++)
		scanf("%d", &a[i]);
	for(int i = 0; i < n; i++)
		scanf("%d", &b[i]);
	int ans = 0;
	int cnt0 = 0;
	for(int i = 0; i < n; i++)
	{
		if(a[i] == 0)
		{
			if(b[i] == 0)
				cnt0++;
		}
		else
		{
			pair<int, int> p = make_pair(-b[i], a[i]);
			norm(p);
			m[p]++;
			ans = max(ans, m[p]);
		}
	}
	cout << cnt0 + ans << endl;
}

#include <bits/stdc++.h>

using namespace std;

int main() {
#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
//	freopen("output.txt", "w", stdout);
#endif
	
	int n, k;
	cin >> n >> k;
	vector<int> a(n);
	for (int i = 0; i < n; ++i) {
		cin >> a[i];
	}
	sort(a.begin(), a.end());
	vector<int> cnt(n);
	for (int i = 0; i < n; ++i) {
		while (i + cnt[i] < n && a[i + cnt[i]] - a[i] <= 5) {
			++cnt[i];
		}
	}
	
	vector<vector<int>> dp(n + 1, vector<int>(k + 1));
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j <= k; ++j) {
			dp[i + 1][j] = max(dp[i + 1][j], dp[i][j]);
			if (j + 1 <= k) {
				dp[i + cnt[i]][j + 1] = max(dp[i + cnt[i]][j + 1], dp[i][j] + cnt[i]);
			}
		}
	}
	
	cout << dp[n][k] << endl;
	
	return 0;
}

#include <bits/stdc++.h>

using namespace std;

int n, m;
vector<vector<int>> g;
vector<int> deg, used;
vector<pair<int, int>> ans;

mt19937 rnd(time(NULL));

void bfs(int s) {
	used = vector<int>(n);
	used[s] = 1;
	queue<int> q;
	q.push(s);
	
	while (!q.empty()) {
		int v = q.front();
		q.pop();
		for (auto to : g[v]) {
			if (used[to]) continue;
			if (rnd() & 1) ans.push_back(make_pair(v, to));
			else ans.push_back(make_pair(to, v));
			used[to] = 1;
			q.push(to);
		}
	}
}

int main() {
#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
//	freopen("output.txt", "w", stdout);
#endif
	
	cin >> n >> m;
	g = vector<vector<int>>(n);
	deg = vector<int>(n);
	for (int i = 0; i < m; ++i) {
		int x, y;
		cin >> x >> y;
		--x, --y;
		g[x].push_back(y);
		g[y].push_back(x);
		++deg[x];
		++deg[y];
	}
	
	int pos = 0;
	for (int i = 0; i < n; ++i) {
		if (deg[pos] < deg[i]) {
			pos = i;
		}
	}
	
	bfs(pos);
	shuffle(ans.begin(), ans.end(), rnd);
	for (auto it : ans) cout << it.first + 1 << " " << it.second + 1 << endl;
	
	return 0;
}

#include <bits/stdc++.h>

using namespace std;

int n, m, D;
vector<vector<int>> g;

int cnt;
vector<int> p, color;
vector<pair<int, int>> ans;

mt19937 rnd(time(NULL));

void bfs(int s, int bad) {
	queue<int> q;
	q.push(s);
	color[s] = cnt;
	while (!q.empty()) {
		int v = q.front();
		q.pop();
		if (p[v] != -1) {
			if (rnd() & 1) ans.push_back(make_pair(p[v], v));
			else ans.push_back(make_pair(v, p[v]));
		}
		for (auto to : g[v]) {
			if (to == bad || color[to] != -1) continue;
			p[to] = v;
			color[to] = cnt;
			q.push(to);
		}
	}
	++cnt;
}

int main() {
#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
//	freopen("output.txt", "w", stdout);
#endif
	
	cin >> n >> m >> D;
	g = vector<vector<int>>(n);
	for (int i = 0; i < m; ++i) {
		int x, y;
		cin >> x >> y;
		--x, --y;
		g[x].push_back(y);
		g[y].push_back(x);
	}
	
	p = color = vector<int>(n, -1);
	cnt = 0;
	for (int i = 1; i < n; ++i) {
		if (color[i] == -1) {
			bfs(i, 0);
		}
	}
	
	if (cnt > D || D > int(g[0].size())) {
		cout << "NO" << endl;
		return 0;
	}
	
	sort(g[0].begin(), g[0].end(), [](int a, int b) {
		return color[a] < color[b];
	});
	
	for (int i = 0; i < int(g[0].size()); ++i) {
		if (i == 0 || color[g[0][i]] != color[g[0][i - 1]]) {
			ans.push_back(make_pair(0, g[0][i]));
		}
	}
	D -= cnt;
	for (int i = 1; i < int(g[0].size()); ++i) {
		if (D == 0) break;
		if (color[g[0][i]] == color[g[0][i - 1]]) {
			ans.push_back(make_pair(0, g[0][i]));
			--D;
		}
	}
	
	g = vector<vector<int>>(n);
	for (auto it : ans) {
		g[it.first].push_back(it.second);
		g[it.second].push_back(it.first);
	}
	ans.clear();
	p = color = vector<int>(n, -1);
	cnt = 0;
	bfs(0, -1);
	
	shuffle(ans.begin(), ans.end(), rnd);
	cout << "YES" << endl;
	for (auto it : ans) {
		cout << it.first + 1 << " " << it.second + 1 << endl;
	}
	
	return 0;
}