#https://atcoder.jp/contests/abc085/tasks/abc085_d
import math
N, H = map(int, input().split(' '))
A = []
B = []
for _ in range(N):
    a, b = map(int, input().split(' '))
    A.append(a)
    B.append(b)
max_A = max(A)
B = sorted(B, reverse=True)
ans = H
for k in range(N):
    H -= B[k]
    if H > 0:
        cnt = math.ceil(H / max_A) + (k + 1)
    else:
        cnt = 0
    ans = min(ans, cnt)
print(ans)