#include <fstream>
#include <limits>
#include <vector>
#include <queue>
#include <tuple>
#include <iostream>

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

int main()
{
    int n, m, a, b;
    fin>>n>>m;
    vector<int> weight(n+1);
    vector<int> profit(m+1);

    for (int i = 1; i <= n; ++i) {
        fin>>a>>b;
        weight[i] = a;
        profit[i] = b;
    }

    vector<vector<int> > dp(2, vector<int>(m+1, 0));
    int l = 0;
    for (int i = 1; i <= n; ++i, l = 1-l) {
        for (int cost = 0; cost <= m; ++cost) {
            if (cost - weight[i] >= 0 )
                dp[1-l][cost] = max(dp[l][cost], dp[l][cost - weight[i]] + profit[i]);
            else
                dp[1-l][cost] = dp[l][cost]; 
        }
    }

    int ret = -1;
    for (int cost = 0; cost <= m; ++cost) {
        ret = max(ret, dp[l][cost]);
    }

    fout<<ret;
    return 0;
 
}