from collections import deque
N,H=map(int,input().split())
a=deque([]);b=deque([])
for _ in range(N):
    ai,bi=map(int,input().split())
    a.append(ai)
    b.append(bi)
bb=deque([])
ma=max(a)
for _ in range(N):
    bi=max(b)
    b.remove(bi)
    if bi>ma:
        bb.append(bi)
    if sum(bb)>=H:
        print(len(bb))
        exit()
ans=(H-sum(bb))//ma+len(bb)
if (H-sum(bb))%ma==0:
    print(ans)
else:
    print(ans+1)