#include <stdio.h>
#include <stdint.h>
uint16_t hex_to_uint(const char *str) {
// Your logic here
uint16_t number = 0;
for(int i=0; str[i]; i++)
{
if(str[i]>='0' && str[i]<='9')
number = (number << 4) | (str[i] - '0');
else if(str[i]>='A' && str[i]<='F')
number = (number << 4) | (str[i] - 'A' + 10);
else if(str[i]>='a' && str[i]<='f')
number = (number << 4) | (str[i] - 'a' + 10);
}
return number;
}
int main() {
char hex[10];
scanf("%s", hex);
printf("%u", hex_to_uint(hex));
return 0;
}