#include<bits/stdc++.h>
using namespace std;
using ll =long long;
#define all(A) A.begin(),A.end()
#define rep(i, n) for (long long i = 0; i < (long long)(n); i++)



int main(){
    string T;
    cin>>T;
    ll H=10*(T[0]-'0')+(T[1]-'0'),M=10*(T[3]-'0')+(T[4]-'0');
    M+=5;
    if(M>=60){
        H++;
        M%=60;
    }
    if(H>=24){
        H%=24;
    }
    cout<<(H<10?"0":"")<<H<<(M<10?":0":":")<<M<<endl;

}