n, h = gets.chomp.split.map(&:to_i)
a_swords = []
b_swords = []
n.times.each do
  input = gets.chomp.split.map(&:to_i)
  a_swords.push input[0]
  b_swords.push input[1]
end
b_swords = b_swords.sort.reverse
a_max = a_swords.max

counts = []

(0..n).each do |k|
  counts[k] = k
  h -= b_swords[k - 1] if k > 0
  counts[k] += (h % a_max).zero? ? h / a_max : h / a_max + 1
end

puts counts.min
