程序代码：

#include<iostream>
using namespace std;

const int size=111;
char a[size],b[size];
int main(){int i,j,k;
    while(cin>>a>>b){
           int s1=strlen(a);
           int s2=strlen(b);
           int c[size]={0},d[size]={0};
                   for(k=0,j=0;k<s1;k++)
              c[j++]=a[s1-1-k]-'0';
           for(k=0,j=0;k<s2;k++)
              d[j++]=b[s2-1-k]-'0';
              int ans[222]={0};
       
        for(i=0;i<s2;i++)   
          for(j=0;j<s1;j++){
               ans[i+j]+=c[j]*d[i];
                     }
             
          for(i=0;i<222;i++){
             if(ans[i]>=10){
                ans[i+1]+=ans[i]/10;
              ans[i]=ans[i]%10;
                }   
                    }
     
     int l=0;
     while(ans[size-1-l]==0&&size-1-l>0)l++;
     for(i=size-1-l;i>=0;i--)cout<<ans[i];
          cout<<endl;
    }
    return 0;
    }