#include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>

using namespace std;

/**
 * 特殊乘法--清华大学
 * @return
 */
int main() {
    string num01;
    string num02;
    //用字符串来接收两个整数
    while (cin >> num01 >> num02) {
        int sum = 0;
        //遍历两个字符串
        for (int i = 0; i < num01.size(); ++i) {
            for (int j = 0; j < num02.size(); ++j) {
                //字符2 - 字符0 = 整数2 - 整数0 = 2
                sum += (num01[i] - '0') * (num02[j] - '0');
            }
        }
        cout << sum << endl;
    }
    return 0;
}