import sys

N, H = [int(x) for x in sys.stdin.readline().strip().split()]
AB = [tuple(int(x) for x in sys.stdin.readline().strip().split()) for i in range(N)]
AB.sort(key=lambda x:(-x[0],x[1]))

r = 1000000000000
for i in range(min(N, 100)):
    p = AB[i][0]
    qs = [AB[j][1] for j in range(N) if AB[j][1] > p]
    rr = ((H - sum(qs) + (p - 1)) // p) + len(qs)
    r = min(r, rr)

print(r)
