import sys
import numpy as np
from bisect import bisect_left

input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)


def main():
    N, H = map(int, input().split())
    A = []
    B = []
    for i in range(N):
        a, b = map(int, input().split())
        A.append(a)
        B.append(b)

    A.sort()
    B.sort()
    for i in range(N):
        if B[i] < A[-1]:
            B[i] = A[-1]
    # print(B)

    # C = A + B
    # C.sort()
    # C = C[-N:]
    # A_cum = np.cumsum(A)
    B_cum = np.cumsum(B)

    # print(A, B, A_cum, B_cum)
    idx = bisect_left(B_cum, H)
    # print("idx", idx)
    if idx <= N - 1:
        print(idx + 1)
    else:
        H -= B_cum[-1]
        # print("H", H)
        need_try = (H + A[-1] - 1) // A[-1]
        print(idx + need_try)


if __name__ == "__main__":
    main()
