# Here your code !

a = gets
b = gets
a_i = a.to_i
b_i = b.to_i

unless 0 <= a_i && a_i <= 12345
  puts "NG"
  exit
end

unless 0 <= b_i && b_i <= 12345
  puts "NG"
  exit
end

unless a == a_i.to_s + "\n"
  puts "NG"
  exit
end

unless b == b_i.to_s + "\n"
  puts "NG"
  exit
end

puts "OK"