#include<iostream>
using namespace std;
int main()
{
string s;
cin >> s;
int h = (s[0]-'0')*10+(s[1]-'0');
int m = (s[3]-'0')*10+(s[4]-'0');
if(m<=54){
cout << h << ":" << m+5 << endl;
}else{
cout << (h+1)%24 << ":" << (m+5)%60 << endl;
}
}