//No.525 二度寝の季節


#include <bits/stdc++.h>
using namespace std;

int main()
{
char S[ 20 ];
int H;
int M;

	cin >> S;
	H = atoi( S );
	M = atoi( S + 3 );

	M += 5;
	if( M >= 60 )
	{
		H++;
		M -= 60;
		if( H >= 24 )	H -= 24;
	}

	printf( "%02d:%02d\n", H, M );

	return 0;
}