program main

  use omp_lib

  integer i, j, m, n
  real f, total, x, y

  total = 0.0
!$omp parallel do private ( i, j, x, y ) shared ( m, n ) reduction ( + : total )
  do j = 1, n
    y = j / real ( n )
    do i = 1, m
      x = i / real ( m )
      total = total + f ( x, y )
    end do
  end do
!$omp end parallel do

  stop
end