#include<bits/stdc++.h>
using namespace std;
const int N = 1e5 + 9;
using ll = long long;
#define inf 10000
int t, k, a[N], b[N];

int check(int x){
    ll sum = 0;
    for(int i = 0; i < t; ++i)
        sum += (a[i] / x) * (b[i] / x);
    return sum >= k;
}

int main(){
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    cin >> t >> k;
    for(int i = 0;i < t; ++i) cin >> a[i] >> b[i];
        int l = 1, r = inf;
        while(l + 1 < r){
		int mid=(l + r) >> 1;
		if(check(mid)) l = mid;
		else r = mid;
	}
    cout << l << "\n";
    return 0;
}