/*
 *  Factorial  ( 30분 끄적인건데 랭크 1위먹었 [...] )
 *  http://220.81.36.44/30stair/factorial/factorial.php?pname=factorial
 *
 */

#include <stdio.h>

#define MM 1000000000

int N;
int i, n, c;
int R[1000], Rl = 1;
long long tmp;

int main()
{
  scanf ("%d", &N);

  R[0] = 1;

  for (n=2; n<=N; n++)
    {
      c = 0;
      for (i=0; i<Rl; i++)
        {
          tmp = (long long)n * (long long)R[i] + (long long)c;

          c = (tmp / MM);
          R[i] = tmp % MM;
        }

      if (c)
          R[Rl++] = c;
    }


  printf ("%d", R[Rl-1]);
  for (i=Rl-2; i>=0; i--)
    {
      printf ("%09d", R[i]);
    }

  return 0;
}