这是一个纯粹的二分模板题
n, k = map(int,input().split())
w = []
for _ in range(n):
w.append(list(map(int,input().split())))
def check(x):
cnt = 0
for a,b in w:
cnt+=(a//x)*(b//x)
return cnt
l,r = 0,1e5+10
ans = 1
while l<r:
mid = (l+r)//2
if check(mid) >=k:
ans=mid
l = mid+1
else:
r = mid
print(int(ans))