#include <bits/stdc++.h>
#define rep(i,n) for (int i=0; i<(n); ++i)
using namespace std;
using ll=long long;
int main(){
    int a;
    cin>>a;
    a*=6;
    a/=10;
    int x,y;
    x=a/60;
    y=a%60;
    if(a==600){
        cout<<"20:00"<<endl;
    }
    else{
        if(y<=9){
            cout<<"1"<<x<<":"<<"0"<<y<<endl;
        }
        else{
            cout<<"1"<<x<<":"<<y<<endl;
        }
    }
}