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

a = []
b = []

n.times do |i|
  a[i], b[i] = gets.split.map(&:to_i)
end

amax = a.max
bb = b.select{|i|i>amax}
bb.sort_by{|i|-i}

atk = 0
bb.each do |thw|
    atk += 1
    h   -= thw
    break if h <= 0 
end

atk += Rational(h, amax).ceil if h > 0

p atk
