var F = Fn.new { |n|
    if (n == 0) return 1
    return n - M.call(F.call(n-1))
}

var M = Fn.new { |n|
    if (n == 0) return 0
    return n - F.call(M.call(n-1))
}

System.write("F(0..20): ")
(0..20).each { |i| System.write("%(F.call(i))  ") }
System.write("\nM(0..20): ")
(0..20).each { |i| System.write("%(M.call(i))  ") }
System.print()