#include <iostream>
#include <iomanip>

using namespace std;

int main()
{ const int n = 7;
  int var = 1;
  int fac = 1;
  while (var <= n)
  { fac = fac * var;
    var = var + 1; }
  cout << "factorial(" << n << ") = " << fac << "\n"; }

/* or with debugging prints

int main()
{ const int n = 7;
  int var = 1;
  int fac = 1;
  while (var <= n)
  { cout << "fac = fac(" << fac << ") * var(" << var << ")\n";
    fac = fac * var;
    cout << "now fac = " << fac << "\n";
    var = var + 1; }
  cout << "factorial(" << n << ") = " << fac << "\n"; }
*/