program test
integer :: a, b, c, d, x, y, z, w
real :: e, f
a = 2 + 4 * (2 + 1) / 3 * b
b = a
if (a > b) then 
    a = x
elif (a > c) then
    a = y
elif (a > d) then
    a = z
else
    a = w
end if
do then
    if (a > b .or. c > b) then
        exit
    end if
    a = a + 1
end do
end program