#include <stdio.h>
#include <stdint.h>
uint16_t hex_to_uint(const char *str) {
uint16_t result = 0;
uint16_t value;
for (int i = 0; str[i]; i++) {
char c = str[i];
if (c <= '9')
value = c - '0';
else if (c <= 'F')
value = c - 'A' + 10;
else
value = c - 'a' + 10;
result = result * 16 + value;
}
return result;
}
int main() {
char hex[10];
scanf("%s", hex);
printf("%u", hex_to_uint(hex));
return 0;
}