import java.util.*;

public class Main {
	public static void main(String[] args){
		Main main = new Main();
		main.solveA();
	}

	private void solveA() {
		Scanner sc = new Scanner(System.in);
		String line = sc.nextLine();
		int h = c2i(line.charAt(0)) * 10 + c2i(line.charAt(1));
		int m = c2i(line.charAt(3)) * 10 + c2i(line.charAt(4));
		m += 5;
		if (m > 60) {
			m -= 60;
			h += 1;
			h = h % 24;
		}
		System.out.printf("%02d:%02d", h, m);
	}

	private int c2i(char c) {
		return c - '0';
	}
}