n,h=map(int,input().split())
A,B=[0]*n,[0]*n
for i in range(n):
  A[i],B[i]=map(int,input().split())
A_max=max(A)
B.sort(reverse=True)
ans=0
for i in B:
  if i > A_max:
    h-=i
    ans+=1
  else:break
if h<0:
  h=0
q = h / A_max
p = q % 1
ans += int(q)
if p>0:
  print(ans+1)
else:
  print(ans)