#include<iostream>
using namespace std;
#define IOS ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)
int n,k,a[100010],b[100010];
int check(int x){
	int ans=0;
	for(int i=0;i<n;i++) ans+=(a[i]/x)*(b[i]/x);
	return ans>=k;
}
int main(){
	IOS;
	cin>>n>>k;
	for(int i=0;i<n;i++) cin>>a[i]>>b[i];
	int l=1,r=100000;
	while(l<r){
		int mid=(l+r+1)>>1;
		if(check(mid)) l=mid;
		else r=mid-1;
	}
	cout<<l;
}