#include<iostream>

using namespace std;

typedef long long ll;

const int N = 100010;

int n, m;
int h[N], w[N];

bool check(int mid)
{
    ll res = 0;
    for(int i = 0; i < n; i ++)
    {
        res += (ll)h[i] / mid * (w[i] / mid);
        if(res >= m) return true;
    }

    return false;
}

int main()
{
    cin >> n >> m;
    for(int i = 0; i < n; i ++) cin >> h[i] >> w[i];

    int l = 1, r = 1e5;
    while(l < r)
    {
        int mid = l + r + 1>> 1;
        if(check(mid)) l = mid;
        else r = mid - 1;
    }
    cout << l << endl;
}