! Napier number
PROGRAM ex6_5

  IMPLICIT NONE
  INTEGER :: k, max, m, n, r, j
  INTEGER, ALLOCATABLE :: keta(:)

  ! input the digits
  PRINT '(1X,A)', 'How many digits do you want to calculate ?'
  READ *, k

  ALLOCATE( keta(k) )
  keta = 0

  ! finding upper limit for m
  max = k * LOG( 10.0E0 )

  ! main loop
  DO m = max, 2, -1
    r = 1
    DO n = 1, k
      j = 10 * r + keta(n)
      keta(n) = j / m
      r = j - m * keta(n)   ! 剰りを繰り越していく
    END DO
  END DO

  PRINT '(//" e = 2.", 10(1X, 5I1)/(7X, 10(1X, 5I1)))', keta

END PROGRAM ex6_5