#include <iostream>
#include <string>
#include <vector>
using namespace std;

string toHexString(int n);

int main() {

    int n;
    cin >> n;

    string hexStr = toHexString(n);
    cout << hexStr << endl;

    return 0;
}

string toHexString(int n) {
    // write your code here......

    string s = "";
    string s1 = "0123456789ABCDEF";

    while (n != 0) {
        int num = n % 16;
        s = s + s1[num] ;
        n = n / 16;
    }
    string s2;
    for (int i = s.length() - 1; i >= 0; i--) {
        s2.push_back(s[i]);
    }
    return s2;

}