#include <stdio.h>


main(){

    char hex[8];
    int i,num;
    int dec = 0;
    int a;

    for(i = 0; i <= 7; i++){
         scanf ("%c", hex[i]);
         if(hex[i] == 'A') num = 10;
         if(hex[i] == 'B') num = 11;
         if(hex[i] == 'C') num = 12;
         if(hex[i] == 'D') num = 13;
         if(hex[i] == 'E') num = 14;
         if(hex[i] == 'F') num = 15;
         else num = hex[i]%30;
         for(a = 7; a >= 0; a--) dec = num*(16^a);
    }
    printf("%d \n", dec);
    system ("pause");
}