N, H = map(int, input().split())
A = []
B = []
for i in range(N):
  a, b = map(int, input().split())
  A.append(a)
  B.append(b)
B = sorted(B, reverse=True)
max_a = max(A)
i = 0 
while (i < N and B[i] > max_a):
  H -= B[i]
  if H <= 0:
    print(i+1)
    exit(0)
  i += 1
print(i + (H + max_a-1)//max_a)
