#include<iostream>
#include<cstdio>
using namespace std;

int char_int(char ca){
	int i;
	char cb;
	for(i=0,cb='0';i<10;i++,cb++){
		if(ca==cb)return i;
	}
}

int main(){
	char ca[10];
	int s[2];
	int i,j,k;
	cin>>ca;
	s[0]=char_int(ca[0])*10+char_int(ca[1]);
	s[1]=char_int(ca[3])*10+char_int(ca[4]);
	s[1]+=5;
	if(s[1]>=60)s[1]%=60,s[0]++;
	if(s[0]>=24)s[0]-=24;
	printf("%02d:%02d\n",s[0],s[1]);
	return 0;
}