arr = []
arr.push gets.chomp
arr.push gets.chomp
x = arr[0].split('.')
y = arr[1].split('.')
flag = false
x.each_with_index do |e, k|
  if e < y[k]
    flag = true
  elsif e == y[k]
  else
    break;
  end
end
puts flag ? 'YES' : 'NO'