N,H=map(int,input().split())
A=[]
B=[]
for i in range(N):
  a,b=map(int,input().split())
  A.append(a)
  B.append(b)

am=max(A)
pop=[]
for i in reversed(range(N)):
  if B[i]<am:
    B.pop(i)
    A.pop(i)

n=0
for i in reversed(sorted(B)):
  if H<=0:
    print(n)
    exit()
  else:
    n+=1
    H-=i

print((H-1)//am+1+n)

