arr = []
arr.push gets.chomp
arr.push gets.chomp
x = arr[0].split('.')
y = arr[1].split('.')
if x[0] == y[0]
  puts arr.sort.reverse == arr ? 'YES' : 'NO'
else
  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'
end