Program to find the value of n-c-r

C      Program to find the value of n-c-r
        integer n,r,i
        real ncr
        write(*,*)'Enter the Positive integers n,r:'
        read(*,*)n,r
        ncr=fact(n)/(fact(r)*fact(n-r))
        write(*,*)'The value of ncr is',ncr
        end
        
C      Program sub function
        function fact(n)
        fact=1
        do i=1,n
        fact=fact*i
        end do
        return
        end