n, h = gets.split.map(&:to_i)

count = 0
katanas = []
n.times { katanas << gets.split.map(&:to_i) }

attack = katanas.sort!{|a, b| b[0] <=> a[0]}.shift

katanas.each do |k|
  if k[1] > attack[0]
    h -= k[1]
    count += 1
  end
end

h -= attack[1]
count += 1

if h > 0
  count += h / attack[0]
  count += (h % attack[0] == 0) ? 0 : 1
end

puts count