#include<iostream>
using namespace std;
int main(){
    char c[5];
    cin>>c[0]>>c[1]>>c[2]>>c[3]>>c[4];
    int a=(c[0]-'0')*10+c[1]-'0';
    int b=(c[3]-'0')*10+c[4]-'0'+5;
    if(b>59){
        b-=60;
        a+=1;
        if(a==24){
            a=0;
        }
    }
    if(a/10==0){
        cout<<0<<a<<':';
    }else{
        cout<<a<<':';
    }
    if(b/10==0){
        cout<<0<<b<<endl;
        return 0;
    }
    cout<<b<<endl;
}