#include<iostream>
#include<string>
using namespace std;

int main() {
    string num1, num2;
    int arr1[100], arr2[100];
    int l1, l2, res;
    while (cin >> num1 >> num2) {
        l1 = num1.length();
        l2 = num2.length();
        for (int i = 0; i < l1; i++) {
            arr1[i] = num1[i] - '0';
        }
        for (int i = 0; i < l2; i++) {
            arr2[i] = num2[i] - '0';
        }
        res = 0;
        for (int i = 0; i < l1; i++) {
            for (int j = 0; j < l2; j++) {
                res += arr1[i] * arr2[j];
            }
        }
        printf("%d\n", res);
    }
}

简单题,其实可以不用两层循环,直接就是两个数的数字和之积