#include <stdio.h>
#include <stdint.h>
uint16_t hex_to_uint(const char *str) {
// Your logic here
uint16_t result = 0;
int i = 0;
uint8_t digit;
while(str[i] != '\0')
{
if(str[i] >= '0' && str[i] <= '9')
digit = str[i] - '0';
else if(str[i] >= 'A' && str[i] <= 'F')
digit = str[i] - 'A' + 10;
else
digit = str[i] - 'a' + 10;
result = result * 16 + digit;
i++;
}
return result;
}
int main() {
char hex[10];
scanf("%s", hex);
printf("%u", hex_to_uint(hex));
return 0;
}