#include <iostream>
using namespace std;

int main() {
	 int sh, sm;
     int fh, fm;
	 scanf("%d:%d", &sh, &sm);
	 scanf("%d:%d", &fh, &fm);
	 int start = sh*60+sm;
	 int finish = fh*60+fm;
	 int way, rest;
	 scanf("%d %d", &(way), &(rest));
	 int x = way + rest;
	 for(int t=start, i=0; t<finish; t+=x, i++){
	 	 printf("%02d:%02d %s", t/60, t%60, i% 2 == 0? "\t":"\n");
	 }
	return 0;
}