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())
ab=sorted(a+b)[::-1]
ans=0
for i in ab[:ab.index(max(a))]:
  h-=i
  ans+=1
  if h<=0:
    print(ans)
    exit()
ans+=(h+max(a)-1)//max(a)
print(ans)