#include <iostream>
using namespace std;

int main()
{
	int a,b;
	cin>>a;
	b=a/5*3;
	cout<<(b/60)+10<<":";
	if(b%60<10)cout<<0<<b%60<<endl;
	else cout<<b%60<<endl;
	fflush (stdin);
	getchar();
	return 0;
}