n,h=map(int,input().split())
A=list(tuple(map(int,input().split())) for i in range(n))
A.sort()
a,b=A.pop(A.index(max(A,key=lambda x:x[0])))

count=0
for i in range(n-1):
    if A[i][1]>=b:
        h -=A[i][1]
        count +=1
        if h<=0:print(count);exit()

count +=1
h -=b
if h<=0:print(count);exit()

if h-a*(h//a)==0:count +=h//a
else:count +=h//a+1

print(count)