N, M = map(int, input().split())
AB = [list(map(int, input().split())) for _ in range(N)]

L = []
for A, B in AB:
    L.append((M-A)//B)
L.sort()

ans = 0
for i in range(N):
    if L[i] == 0:
        ans = max(ans, i+1)
    else:
        ans = max(ans, ((i+1)+L[i])//(L[i]+1))

print(ans)