import sys
from operator import itemgetter
input=sys.stdin.readline
n,x=map(int,input().split())
a=[list(map(int,input().split())) for i in range(n)]
a=list(zip(*a))
t=max(a[0])
a.sort(key=itemgetter(1),reverse=True)
ans=0
for i in range(n):
  if x<=0:
    print(ans)
    break
  if a[1][i]>=t:
    x-=a[1][i]
    ans+=1
  else:
    ans+=(x+t-1)//t
    x=0