#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
using namespace std;
int main()
{
char a[100],b[100];
while(~scanf("%s %s",a,b)){
int len1=strlen(a);
int len2=strlen(b);
int s=0;
for(int i=0;i<len1;++i){
for(int j=0;j<len2;++j){
s+=(b[j]-'0')*(a[i]-'0');
}
}
printf("%d\n",s);
}
return 0;
}