from math import ceil
n,h=map(int,input().split())
g=[list(map(int,input().split())) for i in range(n)]
l=[]
ans=0
dm=0
for i in range(n):
  l.append([g[i][0],2])
  l.append([g[i][1],1])
l.sort(reverse=True)
for i in range(2*n):
  if l[i][1]==1:
    dm+=l[i][0]
    ans+=1
    if dm>=h:
      print(ans)
      exit()
  else:
    h-=dm
    ans+=ceil(h//l[i][0])
    print(ans)
    exit()
    