N,H=list(map(int,input().split()))
a=[0]*N
b=[0]*N

for i in range(N):
    ta,tb=list(map(int,input().split()))
    a[i]=ta
    b[i]=tb

amax=max(a)
b.sort(reverse=True)

res=10**10
csum=0
for i in range(N+1):
    cnt=i
    ch=H
    csum+=b[i-1] if i>0 else 0
    ch-=csum
    
    if H>0:
        cnt+=(ch+amax-1)//amax

    res=min(res,cnt)

print(res)    
