import copy
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)

A.sort()
B.sort()

if A[-1]>=B[-1]:
    print((H-1+A[-1])//A[-1])

cnt=0
ans=[]

while B[-1]>A[-1]:
    H-=B[-1]
    cnt+=1
    if H<=0:
        ans.append(cnt)
        print(min(ans))
        exit()
    elif cnt==N:
        break
    B.pop()

ans.append(cnt+(H-1+A[-1])//A[-1])
print(min(ans))