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