#include <bits/stdc++.h>
using namespace std;



int main(){
    string a,b;
    while(cin >> a >> b){
        int alen = a.length();
        int blen = b.length();
        int count = 0;
        for(int i = 0 ;i<alen;i++){
            for(int j = 0 ; j < blen;j++){
                count = count + (a[i]-'0') * (b[j]-'0');
            }
        }
        cout << count << endl;
    }
}