temp=input()
n=int(temp.split(" ")[0])
h=int(temp.split(" ")[1])
a=[]
b=[]
for i in range(n):
    temp=input()
    ta=int(temp.split(" ")[0])
    tb=int(temp.split(" ")[1])
    a.append(ta)
    b.append(tb)
p=max(a)
q=sum(b)
ans=int(int(h-q)/p)+n
print(ans)