#include <stdio.h>
#include <stdint.h>
uint16_t hex_to_uint(const char *str) {
// Your logic here
int kq=0;
while (*str!='\0'){
if (*str>='0'&&*str<='9'){
kq=kq<<4|(*str-'0');
str++;
}
else if (*str<='F'&&*str>='A') {
kq=kq<<4|(*str-55);
str++;
}
else {
kq=kq<<4|(*str-87);
str++;
}
}
return kq;
}
int main() {
char hex[10];
scanf("%s", hex);
printf("%u", hex_to_uint(hex));
return 0;
}