#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll n, k;
vector<ll> width, height;bool check(ll length)  //判断边长为length的正方形都否满足需求 
{ll sum = 0;  //记录能切成的最大方块数 for(int i = 0; i < n; i++){sum += (width[i] / length) * (height[i] / length);}if(sum >= k) return true;  //如果能切成的方块数大于等于人数 else return false;
}int main()
{ios::sync_with_stdio(false);cin >> n >> k;ll t1, t2;ll sum = 0;for(ll i = 0; i < n; i++){cin >> t1 >> t2;width.push_back(t1);height.push_back(t2);sum += t1 * t2;  //计算巧克力的总面积 }ll res = sqrt(sum / k);  //sum除以k是每个人最多可以分配到的巧克力面积，//开根号即表示可能的最大边长数 ll left = 1, right = res, mid;while(left <= right)  //使用二分法搜索最大边长 {mid = (left + right) / 2;if(check(mid))  //判断边长为mid时是否满足分配需求 left = mid + 1;elseright = mid - 1;}cout << left - 1;  return 0;
}