from math import ceil
import sys

N,H = map(int,input().split())
maxA = -float('inf')
B = []
for _ in range(N):
  a,b = map(int,sys.stdin.readline().split())
  maxA = max(maxA,a)
  B.append(b)

B.sort(reverse=True)

ans = float('inf')
pointB = 0
for nb in range(N+1):
  if nb != 0: pointB += B[nb-1]
  ans = min(ans,ceil((H-pointB)/maxA)+nb)
print(ans)