import math

N, H = map(int, input().split())
Swords_a = []
Swords_b = []
amax = 0
for i in range(N):
  
  a, b = map(int, input().split())
  Swords_a.append(a)
  Swords_b.append(b)
  
ma = max(Swords_a)
sb = 0 # bのうち「maより大きい成分」の和

Swords_a = sorted(Swords_a)
Swords_b = sorted(Swords_b)

c = 0
k = 0

for i in range(N):
  if ma < Swords_b[i]:
    sb += Swords_b[i]
    c += 1
  if sb >= H:
    k = c
    どーん！
    break

if sb < H:
  print(c + math.ceil((H-sb)/ma))
else:
  #こっちでWAになる
  print(k)