program Pi
implicit none
! -----------------------------------------------Declare
real*8 lengtha,lengthb,lengthc,pi,redpoints
integer*4 nrtries,i
! -----------------------------------------------Input
print*, "Enter the number of points:"
read*, nrtries
redpoints = 0
! -----------------------------------------------Compute
do i=1,nrtries
lengtha = rand(0)
lengthb = rand(0)
lengthc = dsqrt(lengtha**2 + lengthb**2)
if (lengthc < 1) then
    redpoints + 1;
endif
nrtries +1
i + 1
end do
pi = 4*(redpoints / nrtries)
! -----------------------------------------------Output
print*, "The approximate value of PI is: "
print*, pi
end