#include <bits/stdc++.h>
using namespace std;
int a[100005], b[100005];
int f(int x, int n, int k){
	int ans = 0;
	for(int i = 1; i <= n; i++)
		ans += (a[i]  / x) * (b[i] / x);
	return ans;
}
int main(){
	int n, k, ans;
	ios::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);
	cin >> n >> k;
	int l = 1, r = 1000000;
	for(int i = 1; i <= n; i++){
		cin >> a[i] >> b[i];
	}
	while(l < r){
		int mid = (l + r) / 2;
		if(f(mid, n, k) >= k){
			ans = mid + 1;
			l = mid + 1;
		}
		else r = mid - 1;
	}
	cout << ans;
}