#include<bits/stdc++.h>
using namespace std;
int n,k,h[100005],w[100005];
bool jud(int x){
	int c=0;
	for(int i=1;i<=n;i++)c+=(h[i]/x)*(w[i]/x);
	return c>=k;
}  
int main(){
	cin>>n>>k;
	for(int i=1;i<=n;i++)cin>>h[i]>>w[i];
	int l=1,r=100000;
	while(l<r){
		int mid=(l+r+1)/2;
		if(jud(mid))l=mid;
		else r=mid-1;
	}
	cout<<l;
    return 0;
}