// yukicoder: No.525 二度寝の季節
// 2019.4.18 bal4u

#include <stdio.h>
#include <ctype.h>

#define gc() getchar()
int in()
{
	int n = 0, c = gc();
	do n = 10 * n + (c & 0xf), c = gc(); while (isdigit(c));
	return n;
}

int main()
{
	int t = (in()*60+in()+5) % 1440;
	printf("%02d:%02d\n", t/60, t%60);
	return 0;
}