题解 | #特殊乘法#

#include <bits/stdc++.h>

using namespace std;

int main(){
	string s1,s2;
	
	while(cin >> s1 >> s2){
		int ans = 0;
		for(int i = 0;i < s1.size();i ++){
			for(int j = 0;j < s2.size();j ++){
				ans += (s1[i] - '0') * (s2[j] - '0');
			}
		}
		cout << ans << endl;
	} 
	return 0;
}