#include<bits/stdc++.h> 
using namespace std;
#define ll long long 
#define ss string
int main()
{
	ll a,b;
	char w;
	cin>>a>>w>>b;
	if(a<6) a+=24;
	if(a<10) cout<<0;
	cout<<a;	
	cout<<w;
	cout<<b;
}

感觉没什么问题