题解 | #特殊乘法#

int main(){
    long a,b;
    while(scanf("%ld %ld",&a,&b) != EOF){
        long sum = 0;
        while(a){
            int temp = b;
            while(temp){
                sum += (temp % 10) * (a % 10);
                temp /= 10;
            }
            a /= 10;
        }
        printf("%ld\n",sum);
    }
}