import sys
import numpy as np

read = sys.stdin.read
sys.setrecursionlimit(10**9)

n, h = map(int, input().split())
d = np.array(read().split(), dtype=np.int64).reshape([-1,2])

a = np.max(d[:,0])
b = d[:,1][np.argsort(d[:,1])][::-1]
b = b[b > a]
B = np.cumsum(b)
if B[-1] < h:
    ans = -(-(h-B[-1])//a) + len(B)
else:
    ans = np.searchsorted(B, h) + 1
print(ans)