-- create two-dimensional array with random numbers
a = []
repeat with i = 1 to 20
  a[i] = []
  repeat with j = 1 to 20
    a[i][j] = random(20)
  end repeat
end repeat

-- iterate over rows and columns, print value, exit both loops if it's 20
repeat with i = 1 to 20
  repeat with j = 1 to 20
    v = a[i][j]
    put v
    if v=20 then exit repeat
  end repeat
  if v=20 then exit repeat
end repeat