#include <stdio.h>

int factorial( int n )
{
    if ( n <= 1 )
        return 1;
    else
        return  n * factorial( n-1 );
}

/*-------- main( ) starts here ------------------*/
int main(void)
{
    int N;
    int f;

    printf( "Enter n: " );
    scanf( " %i", &N );

    f = factorial( N );

    printf( "factorial of %i is %i\n", N, f);

    return 0;
}