Java :

import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int a = input.nextInt();
		int num = a;
		int i = a;
		String p = "";
		while (i != 0) {
			a = i % 16;
			if (a == 15)
				p = "F" + p;
			else if (a == 14)
				p = "E" + p;
			else if (a == 13)
				p = "D" + p;
			else if (a == 12)
				p = "C" + p;
			else if (a == 11)
				p = "B" + p;
			else if (a == 10)
				p = "A" + p;
			else
				p = a + p;
			i = i / 16;
		}
		System.out.print(num + "'s hex representation is " + p);
	}
}