#include<stdio.h>
#include<string.h>
#include<math.h>

long long n[1000000], rez;

void citire()
 { char sir[102];
   freopen("patrate2.in","r",stdin);
   freopen("patrate2.out","w",stdout);
   int a, i;
   scanf("%s",&sir);
   a = strlen(sir);
   n[0]= a;
   for (i = 0; i < a; i++)
    n[a-i] = sir[i] - '0';
   for (i=n[0]; i>=1; i--)
     rez=rez*10+n[i];

}

void inmultire(long long A[], long long B)
{
      int i, t = 0;
      for (i = 1; i <= A[0] || t; i++, t /= 10)
	      A[i] = (t += A[i] * B) % 10;
      A[0] = i - 1;
}

int main()
{
  citire();
  long long i;
  n[0]=1; n[1]=2;
  for (i=1; i<rez*rez; i++)
    inmultire(n,2);
  for (i=2; i<=rez; i++)
     inmultire(n,i);
  for (i=n[0]; i>=1; i--)
    printf("%lld",n[i]);
    return 0;

}