How long can an integer be: for loop to compute a factorial

03.fact.cpp

// 03.fact.cpp
// juanfc 2003-11-11
// How long can an integer be:
// for loop to compute a factorial

#include <iostream>
using namespace std;

int main()
{

	cout << "n?: ";
	unsigned int n;
    cin >> n;

    unsigned long long int f = 1;
    for (int i = 2; i < n; ++i) {
    	f *= i;
    }

    cout << n << "!: " << f << endl;
    return 0;
}