为什么会出现TLE？

# include <iostream>
using namespace std;
int main()
{
	int s = 0, n;
	cin >> n;
	while(n != 1)
	{
		if(n % 2 == 0) n /= 2;
		else if(n % 2 != 0)
		{
			n *= 3;
			n += 1;
		}
		s++; 
	}
	cout << s;
	return 0;
}