n,m=map(int,input().split())
l=[]
from math import ceil 
maxia=0 
maxib= 0 
for i in range(n):
    a,b=map(int,input().split())
    l.append([a,b])
    if a>=maxia:
        maxia=a 
        ind=i 
    if b>maxib: 
        maxib=b  
sm=0 
have=[] 
for i in range(n): 
    if l[i][1]>=maxia and i!=ind:
        have.append(l[i][1])
cnt=0 
ans=None
s= 0 
cnt=0 
#print(have)
for i in range(len(have)): 
    m=m-have[i]
    cnt+=1 
    s+=have[i]
    if m<=0: 
        print(i+1)
        exit()
ans=len(have)
if l[ind][1]>maxia: 
    m-= l[ind][1]
    ans+=1 
if m<=0:
    print(ans)
    exit()
print(ans+ceil(m/maxia))