a = a.chomp.split("")
b = b.chomp.split("")
c = 0
if a[0] == "0" && a.size != 1
  c = 1
else
  a.each_index do |i|
    if a[i] =~ /\D/
      c = 1
      break
    end
  end
end
if c == 1
elsif b[0] == "0" && b.size != 1
  c = 1
else
  b.each_index do |i|
    if b[i] =~ /\D/
      c = 1
      break
    end
  end
end
if c == 0
  if a.join.to_i <= 12345 && b.join.to_i <= 12345
    puts "OK"
  else
    puts "NG"
  end
else
  puts "NG"
end