#include<fstream.h>
int a[10000];
int len=1;
void mult(int x)
{
int j;
for (j=1;j<=len;j++) a[j]*=x;
len+=10;
for (j=1;j<=len;j++)
 {
  a[j+1]+=a[j]⁄10;
  a[j]=a[j]%10;
 }
a[0]=1;
 while (a[len]==0) len--;
 if (len==0) len=1;
}
void main()
{
int i,n;
ifstream cin;
ofstream cout;
cin.open ("input.txt",ios::in);
cout.open ("output.txt",ios::out|ios::trunc);
 cin >> n;
 a[1]=1;
 for (i=2;i<=n;i++)
  mult(i);
 for (i=len;i>=1;i--) cout << a[i];
}