//while ӳ
//---------------------------------------------------------------------------
#include <vcl.h>
#include <iostream.h>
#pragma hdrstop
//---------------------------------------------------------------------------
#pragma argsused
int main(int argc, char* argv[])
{
    long sum = 1;
    int n,i;
    cin>>n;
    i = 1;
    while(i<=n)
    {
        sum = sum * i;
        i++;
    }
    cout<<sum;
    return 0;
}
//---------------------------------------------------------------------------


//do whileӳ
//---------------------------------------------------------------------------
#include <vcl.h>
#include <iostream.h>
#pragma hdrstop

//---------------------------------------------------------------------------
#pragma argsused
int main(int argc, char* argv[])
{
    long sum = 1;
    int n,i;
    cin>>n;
    i = 1;
    do
    {
        sum = sum * i;
        i++;
    }while(i<=n);
    cout<<sum;

    getchar();getchar();
    return 0;
}
//---------------------------------------------------------------------------
