n,k = map(int,input().split())
L = []
for i in range(n):
    a,b = map(int,input().split())
    L.append([a,b])
L.sort(reverse = True)
#print(L)
huru = L[0][0]

p = 0
cnt = 0
for i in range(n):
    if L[i][1] > huru:
        p +=L[i][1]
        L[i][1] = 0
        cnt +=1

k -=p
k = max(k,0)


L.sort(reverse = True,key = lambda x:x[1])

huru_ = L[0][1]
b = k%huru
c = k//huru

if huru >= huru_:
    if b == 0:
        print(c+cnt)
    else:
        print(c+1+cnt)
else:
    k -= huru_
    if k%huru == 0:
        print(k//huru+1+cnt)
    else:
        print(k//huru+2+cnt)