n, h =  map(int, input().split())
A = [0]*n
B = [0]*n 
for i in range(n):
  A[i], B[i] = map(int, input().split())
A.sort(reverse=True)
B.sort(reverse=True)

c = 0
for j in range(n):
  if B[j] >= A[0]:
    c += 1
    h -= B[j]
    if h < 0:
      print(c)
      exit()
  else:
    break
if h%A[0] == 0:
  c += h//A[0]
else:
  c = h//A[0]+1
print(c)

