n,h=map(int,input().split())
d=[]
mx=-1
sm=0
for i in range(n):
    a,b=map(int,input().split())
    mx=max(mx,a)
    d.append([b,a])
da=[]
for i in range(n):
    if d[i][0]>mx:
        da.append(d[i])
da=sorted(da,reverse=True)
i=0
for x in da:
    i+=1
    sm+=x[0]
    if sm>=h:
        print(i)
        exit()
da=sorted(da,key= lambda x:-x[1])
print(i+int((h-sm)/da[0][1]+0.5))

