#include <stdio.h>
#include <stdint.h>
void print_hex(uint16_t num) {
if(num==0){putchar('0');return;}
for(int i = 3; i >= 0; i--){
uint8_t nibble = ((num >> (i * 4)) & 0x0F);
if(nibble){
putchar(nibble > 10 ? 'A' + nibble - 10 : '0' + nibble);
}
}
}
int main() {
uint16_t num;
scanf("%hu", &num);
print_hex(num);
return 0;
}