import bisect
n,h = map(int,input().split())
la,lb = [],[]

for i in range(n):
    a,b = map(int,input().split())
    la.append(a)
    lb.append(b)
la.sort(reverse = True)
lb.sort()

sep = bisect.bisect(lb,la[0])
larger = lb[sep:]
sum_larger = sum(larger)

h -=sum_larger
cnt = len(larger)

if h%la[0] == 0:
    print(h//la[0] + cnt)
else:
    print(h//la[0] + cnt+1)
