#include<stdio.h>
int rec(int);
main()
{
    int a, fact ;
    printf ( "Enter any number : " ) ;
    scanf ( "%d", &a ) ;
    fact = rec ( a ) ;
    printf ( "Factorial value = %d \n", fact ) ;
    system("pause");
}
int rec ( int x )
{
    int f ;
    if ( x == 1 )
       return ( 1 ) ;
    else
        f = x * rec ( x - 1 ) ;
    return ( f ) ;
}