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


int main(){
	int a,b;
	char ch;
	scanf("%d%c%d",&a,&ch,&b);
	
	b+=5;
	if(b+5>=60){
		b-=60;
		if(a+1>=24) a=0;
	}
	printf("%02d:%02d\n",a,b);
	
	return 0;
}