#include <stdio.h>
#include <string.h>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <vector>
#define inf 100000
using namespace std;
int n, k;
int choco[inf+5][2];
int mint = inf;
int ans = 0;
bool isright(int length){
long long sum = 0;
for(int i = 0; i < n; i++){
sum += (choco[i][0]/length) * (choco[i][1]/length);
if(sum >= k){
ans = length;
return true;
}
}
return false;
}
int main(){
scanf("%d %d", &n, &k);
for(int i = 0; i < n; i++){
scanf("%d %d", &choco[i][0], &choco[i][1]);
int temp = min(choco[i][0], choco[i][1]);
if(mint < temp)
mint = temp;
}
int left = 0;
int right = mint + 1;
while(left + 1 < right){
int mid = (left + right) / 2;
if(isright(mid))
left = mid;
else
right = mid;
}
cout << ans << endl;
return 0;
}