function myout(text){console.log(text);}//standard output
function Main(input) {
	input = parseInt(input);
	//input = input.trim().split(" ");
	//input = input.trim().split("\n");
	//input = input.trim().split(" ").map((a)=>Number(a));
	//input = input.trim().split("\n").map((a)=>Number(a));
	var vals = getDivisorList(input);
	var output = 0;
	for(var i = 0; i < vals.length; i++){
	    output += vals[i];
	}
	myout(output);
}

function getDivisorList(val){
	var list = [];
	for(var i = 1; i * i <= val; i++){
		if(val % i == 0){
			list.push(i);
			if(i * i != val){
				list.push(val / i);
			}
		}
	}
	list.sort(function(a,b){
		return a - b;
	});
	return list;
}

Main(require("fs").readFileSync("/dev/stdin", "utf8").trim());