module series !Aqui le estoy enseñando a Fortran la funcion factorial
	
	contains
		
	function factorial(n)
		
	integer,intent(in) :: n
	integer :: factorial,k,P
		
		p=1

		do k=1,n
			
			p=p*k
		
		end do
		
		factorial=p

	end function
	
end module

program sumaseries
	use series
implicit none

			
	

	real:: S
	integer :: i

	S=0.

	do i=1,100

		S=S+(1./factorial(i))

			if ( (factorial(i)/S) <= epsilon(S)) then
				exit
			end if

	end do

write (*,*) 'S=' , S

end program