import java.util.*;
import java.lang.*;
import java.io.*;

class Main {
	public static void main (String[] args) throws java.lang.Exception {
		Scanner read = new Scanner(System.in);
		int sh = read.nextInt();
		//char sym = read.nextChar();
		int sm = read.nextInt();
		int fh = read.nextInt();
		int fm = read.nextInt();
		int way = read.nextInt();
	 	int rest = read.nextInt();
		int start = sh*60 + sm;
	 	int finish = fh*60 + fm;
	 	int x = way + rest;
	 	for(int t = start, i = 0; t < finish; t += x, i++){
	 		System.out.print(t/60+":"+t%60);
	 		if(i%2 == 0)
	 			System.out.print("\t");
	 		else
	 			System.out.print("\n");
	 	}
	}
}