// PULL-DP KNAPSACK optimised

#include <bits/stdc++.h>
//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")

//#define fin cin
//#define fout cout

using namespace std;
ifstream fin("rucsac.in");
ofstream fout("rucsac.out");

const int MAX_WEIGHT = 10000, MAX_OBJECTS = 5000;

int n,w;
pair<int,int> objects[MAX_OBJECTS + 1];


// dp[weight][numberOfObjects]
int dp[MAX_WEIGHT + 1];

int ans = 0;

int main() {

    fin >> n >> w;
    for (int i = 1; i <= n; i++) {
        int a,b;
        fin >> a >> b;
        objects[i] = {a,b};
    }

    dp[0] = true;
    for (int it = 1; it <= n; it++) {
        const pair<int,int>& object = objects[it];
        for (int weight = w; weight >= 0; weight--) {
            const int calc = weight + object.first;
            if (dp[weight] and calc <= w) {
                dp[calc] = max(dp[calc], dp[weight] + object.second);
                ans = max(ans, dp[calc]);
            }
        }
    }

    fout << ans - 1;

    return 0;
}