n, h = gets.chomp.split.map(&:to_i)
inputs = n.times.map { |_| gets.chomp.split.map(&:to_i) }
counts = []

a_swords = inputs.map { |input| input[0].to_i }
b_swords = inputs.map { |input| input[1].to_i }.sort!.reverse

(0..n).each do |k|
  counts[k] = k
  rest = h
  rest -= b_swords[0..(k - 1)].sum if k > 0

  counts[k] += (rest % a_swords.max).zero? ? rest / a_swords.max : rest / a_swords.max + 1
end

puts counts.min
