#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<string>
#include<stack>
#include<queue>
#include<vector>
#include<algorithm>
#include<iomanip>
typedef long long int ll;
using namespace std;
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define REP(i,n) for (int i=0;i<(n);i++)
#define EREP(i,n) for (int i=1;i<=(n);i++)
const int MOD = 1000000007;
const int INF = 1000000;
    string S;
     int H,M;
int main(){
    ios::sync_with_stdio(false);
    cin>>S;
    H=stoi(S.substr(0,2));
    M=stoi(S.substr(3,2));
    M+=5;
    if(M>=60){
        M=M-60;
        H++;
    }
    H==24?H=0:H=H;
    cout<< setfill('0') << setw(2)<<H<<":"<< setw(2)<<M<<endl;
}