import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class No00000525_Main {
	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	public static void main(String[] args) throws IOException {
		String[] t = br.readLine().split(":");
		int h = Integer.parseInt(t[0]);
		int m = Integer.parseInt(t[1]);
		System.out.println(String.format("%02d:%02d", (h + ((m + 5) / 60)) % 24, (m + 5) % 60));
	}
}