#include <fstream>

using namespace std;

// Returns the value of maximum profit
int knapSackRec(int W, int wt[], int val[], int index, int** dp)
{
    // base condition
    if (index < 0)
        return 0;
    if (dp[index][W] != -1)
        return dp[index][W];

    if (wt[index] > W) {

        // Store the value of function call
        // stack in table before return
        dp[index][W] = knapSackRec(W, wt, val, index - 1, dp);
        return dp[index][W];
    }
    else {
        // Store value in a table before return
        dp[index][W] = max(val[index]
                           + knapSackRec(W - wt[index], wt, val,
                                         index - 1, dp),
                       knapSackRec(W, wt, val, index - 1, dp));

        // Return value of table after storing
        return dp[index][W];
    }
}

int knapSack(int W, int wt[], int val[], int n)
{
    // double pointer to declare the
    // table dynamically
    int** dp;
    dp = new int*[n];

    // loop to create the table dynamically
    for (int i = 0; i < n; i++)
        dp[i] = new int[W + 1];

    // loop to initially filled the
    // table with -1
    for (int i = 0; i < n; i++)
        for (int j = 0; j < W + 1; j++)
            dp[i][j] = -1;
    return knapSackRec(W, wt, val, n - 1, dp);
}

int main()
{
    ifstream in("energii.in");
    ofstream out("energii.out");
    int g,w,e[10001],c[10001];

    in >> g >> w;

    for(int i=0; i<g; i++)
    {
        in >> e[i] >> c[i];
    }

    out << knapSack(w,e,c,g);


    return 0;
}