N, H = input().strip().split(' ')
N, H =[int(N),int(H)]
L =list()
for i in range(0,N):
    X, Y = input().strip().split(' ')
    X, Y =[int(X), int(Y)]
    L.append([X,Y])

L0 = list()
for i in range(0,N):
    L0.append(L[i][0])

L1 = list()
for i in range(0,N):
    L1.append(L[i][1])

M = max(L0)
L2 = list()

for i in range(0,N):
    if L1[i] > M:
        L2.append(L1[i])

L2 = sorted(L2)

count = 0

for i in range(0,len(L2)):
    if H > 0:
        H -= L2[i]
        count += 1
        if H <= 0:
            print(count)

for i in range(0,N):
    if H > 0:
        H -= M
        count += 1
        if H <= 0:
            print(count)
