/*
 ID: bradyawn
 PROG: contest
 LANG: C++11
 */
 
#include <iostream>
#include <algorithm>
#include <iomanip>
#include <fstream>
#include <vector>
#include <deque>
#include <string>
#include <cmath>
#include <map>
#include <unordered_map>
#include <utility>
#include <set>
#include <unordered_set>
#include <ctime>
#include <queue>
#include <stack>
#include <bitset>
#include <random>
#include <cstring>
#include <functional>
 
using namespace std;
 
typedef long long ll;
typedef pair<int,int> i2;
typedef pair<ll,ll> ll2;
 
int dp[250001]; //maximize talent
 
int w[251];
int t[251];
 
int n, wReq;
 
int main()
{
    //ifstream inf("talent.in");
    //ofstream outf("talent.out");
    //outf << setprecision(10);
   // ios_base::sync_with_stdio(0); inf.tie(0);
 
    cin >> n >> wReq;
 
    int mxTalent = 0;
 
    for (int i = 1; i <= n; i++)
    {
        cin >> w[i] >> t[i];
        mxTalent += t[i];
    }
 
    for (int i = 1; i <= 250000; i++) dp[i] = 1e9;
 
    for (int i = 1; i <= n; i++) //considering item i
    {
        for (int j = mxTalent; j >= 0; j--) //knapsack talent j
            if (j - t[i] >= 0) dp[j] = min(dp[j], dp[j-t[i]] + w[i]);
    }
 
    int ans = 0;
 
    for (int i = 1; i <= mxTalent; i++)
        if (dp[i] >= wReq) ans = max(ans, int(1000.0*i/dp[i]));
 
    cout << ans << '\n';
 
    return 0;
 
}

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5 7
5 100
2 20
2 20
2 20
2 20