n,hp=map(int,input().split(" "))
la=[0 for i in range(n)]
lb=[0 for i in range(n)]
for i in range(n):
    la[i],lb[i]=map(int,input().split(" "))
cnt=0
ma=max(la)
lma=[i for i ,x in enumerate(la)  if x==ma]
mib=10**9
for i in lma:
    if lb[i]<mib:
        mib=lb[i]
        k=i
for i in range(n):
    if lb[i]>ma and i!=k:
        hp-=lb[i]
        cnt+=1
        if hp<0:
            print(cnt)
            exit(0)
        if hp<lb[k]:
            print(cnt+1)
            exit(0)
while hp>0:
    hp-=ma
    cnt+=1
    if hp<lb[k]:
        print(cnt+1)
        exit(0)
print(cnt)