import heapq as hq
from math import ceil
N, H = map(int, input().split())
ab = [tuple(map(int,input().split())) for _ in range(N)]
ab.sort(key=lambda x:x[1], reverse=True)
ab.sort(key=lambda x:x[0], reverse=True)
ma, mb = ab[0]
ab = ab[1:]
q = []
for _,b in ab:
    if b > ma:
        hq.heappush(q, b)
ans = float("inf")

for l in range(len(q)+1):
    h = H
    cnt = l
    h -= sum(q[:l])
    if h <= 0:
        ans = min(ans, cnt)
        continue
    h -= mb
    cnt += 1
    if h <= 0:
        ans = min(ans, cnt)
        continue
    cnt += ceil(h/ma)
    ans = min(ans, cnt)
print(ans)