// using while-loop to calculate n! (factorial of n)
#include <iostream>
#include <math.h>
using namespace std;
int n, x, i;

int main()
{
  n = 5;
  i = 1;
  x = 1;

  while (i<=n){
    x = x * i; 
    i = i + 1; 
  }
  cout << x << endl;
}