def gcd(a,b)
	if(b==0) then
		return a;
	end
	return gcd(b,a%b);
end

def s(n)
	ret = 1;
	i = 2;
	while (i*i <= n) do
		tmp = i;
		while (n%i == 0) do
			tmp *= i;
			n /= i;
		end
		ret *= (tmp-1) / (i-1);

		i += 1;
	end

	if n!=1 then
		i = n;
		tmp = i;
		while (n%i == 0) do
			tmp *= i;
			n /= i;
		end
		ret *= (tmp-1) / (i-1);
	end

	return ret;
end

n = gets.to_i;
v = gcd(n, n*(n-1)/2);
puts s(v);