#include <stdio.h>
 #include <string.h>
 int isPalindrome(char str[]){
     int i=0,j=strlen(str)-1;
     while(i<j){
         if(str[i] != str[j])
         return 0;
         i++;
         j--;
     }
     return 1;
 }
 void multiple(char num1[],char num2[]){
     int len1=strlen(num1);
     int len2=strlen(num2);
     int result[len1 + len2];
     
     for(int i=0;i<len1 + len2;i++)
      result[i] =0;
      
      for (int i=len1-1;i>=0;i--){
          for(int j=len2;j>=0;j--){
              int mul=(num[i]-'0')*(num2[j]-'0');
              int sum=mul+result[i+j+1];
              
              result[i+j+1]=sum%10;
              result[i+j+]+=sum/10;
          }
      }
      int i=0;
      while (i<len1+len2 && result[i]==0)
      i++;
      
      if(i==len1 +len2){
          printf("0");
          return;
      }
      for(; i<len1+len2; i++)
      printf("%d",result[i]);
 }
 int main(){
     char num1[1001],num2[1001];
     
     scanf("%s",num1);
     scanf("%s",num2);
     if(isPalindrome(num) || !isPalindrome(num2)){
         printf("Invalid input");
         return 0;
     }
     multiply(num1,num2);
     
     return 0;
 }