(function() {
	var
		S = parseInt(require('fs').readFileSync('/dev/stdin').toString()),
		date = new Date(S * 1000),
		str = "";
	str = str + String(date.getUTCHours());
	str = str + ":";
	str = str + String(date.getUTCMinutes());
	str = str + ":";
	str = str + String(date.getUTCSeconds());
	console.log(str);
}) ();