#include <bits/stdc++.h>

using namespace std;

/*
 * Complete the 'xorAndSum' function below.
 *
 * The function is expected to return an INTEGER.
 * The function accepts following parameters:
 *  1. STRING a
 *  2. STRING b
 */
 
 
unsigned long long int convert(string s)
{
    reverse(s.begin(), s.end());
    
    unsigned long long int ans = 0;
    unsigned long long int n = s.length();
    
    unsigned long long int mul =1 ;
    for(unsigned long long int i = 0 ; i<n; i++)
    {
        ans+=mul*(s[i]=='1');
        mul*=2;
    }
    
    return ans ;
}

unsigned long long int xorAndSum(string a, string b) {
    
    unsigned long long int mod = 1000000007;
    unsigned long long int a1 = convert(a);
    unsigned long long int b1 = convert(b);
    long long int ans  =0 ;

        cout<<a1<<endl;
    cout<<b1<<endl;
    for(int i =0  ; i <=314159  ; i++)
    {
        
        unsigned long long int bn = (b1<<i)%mod;
        
        ans = (ans + (a1^bn)%mod)%mod;
        
        // b1= (b1*2)%1000000007;
        
        // cout<<ans<<endl;
        
    }
    

    return ans ;
    
}

int main()
{
    ofstream fout(getenv("OUTPUT_PATH"));

    string a;
    getline(cin, a);

    string b;
    getline(cin, b);

     long long int result = xorAndSum(a, b);

    fout << result << "\n";

    fout.close();

    return 0;
}