#include <stdio.h>
#include <stdint.h>
void print_hex(uint16_t num) {
// Your logic here
if(num == 0){
putchar('0');
}
else{
char hex_digits_array[] = "0123456789ABCDEF";
char buffer[5];
int i=0;
while(num > 0){
buffer[i++] = hex_digits_array[num % 16];
num /= 16;
}
for(int j=i-1; j>=0; j--){
putchar(buffer[j]);
}
}
}
int main() {
uint16_t num;
scanf("%hu", &num);
print_hex(num);
return 0;
}