#include <iostream>
using namespace std;
int main()
{
int n, m, temp;
//余数remainder 进位carry_bit
int remainder=0, carry_bit=0;
cin>>m;
int a[10000];
for(int i=0; i<10000; i++) a[i]=0;
a[1] = 1;
for(int n=2; n<=m; n++)
{
remainder=0, carry_bit=0;
for(int i=1; i<10000; i++)
{
temp = a[i]*n+carry_bit;
remainder = temp%10;
carry_bit = temp/10;
a[i] = remainder;
}
}
int i=9999;
while(a[i]==0) i--;i++;
while(--i!=0) printf("%d", a[i]);
return 0;
}