#include <stdio.h>
#include <stdint.h>
void print_hex(uint16_t num) {
// Your logic here
char tmp[4] = {0};
int count = 0;
char hex[17] = "0123456789ABCDEF";
if (num == 0) {
printf("0");
return;
}
for(int i = 0; num > 0; i++) {
tmp[i] = hex[num % 16];
num /= 16;
count++;
}
for(int i = 0; i < count; i++) {
printf("%c", tmp[count - 1 - i]);
}
}
int main() {
uint16_t num;
scanf("%hu", &num);
print_hex(num);
return 0;
}