import math
def main():
    N,H = map(int, input().split())
    a = [None] * N
    b = [None] * N
    for i in range(N):
        a[i], b[i] = map(int, input().split())
    
    a.sort(reverse=True)
    b.sort(reverse=True)

    m = N
    for i in range(N):
        if b[i] > a[0]:
            continue
        else:
            m = i
            break
    
    for i in range(m):
        H -= b[i]
    
    print(math.ceil(H / a[0]) + m)


if __name__ == "__main__":
    main()
