C :

#include<stdio.h>
int main()
{
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        int m,x;
        m=1;
        for(int i=1; i<=n; i++)
        {
            m=m*i;
        }
        x=m/n;
        printf("%d\n",x);
    }
    return 0;
}

C++ :

#include<stdio.h>
#include<iostream>
using namespace std;
int main()
{
	int n,sum;
	//freopen("in1.txt","r",stdin);
	//freopen("out.txt","w",stdout);
	while(cin>>n)
	{
      sum = 1;
	  for(int i=1; i<n; i++)
		  sum=sum*i;
	  cout<<sum<<endl;
	}
	return 0;
}

Pascal :

program zuhe3;
var
 i,n,s:longint;
begin
 while not eof do
  begin
   readln(n);
   s:=1;
   for i:= n-1 downto 2 do s:=s*i;
   writeln(s);
  end;
end.