import java.io.*;
import java.util.*;

public class Main {
    static Pizza[] pizzas;
    static int[][][] dp;
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int k = sc.nextInt();
        pizzas = new Pizza[n];
        for (int i = 0; i < n; i++) {
            pizzas[i] = new Pizza(sc.nextInt(), sc.nextInt());
        }
        Arrays.sort(pizzas);
        dp = new int[n][k + 1][2];
        for (int[][] arr1 : dp) {
            for (int[] arr2 : arr1) {
                Arrays.fill(arr2, -1);
            }
        }
        System.out.println(dfw(n - 1, k, 0));
    }
    
    static int dfw(int idx, int value, int type) {
        if (value < 0) {
            return Integer.MIN_VALUE;
        }
        if (idx < 0) {
            return 0;
        }
        if (dp[idx][value][type] < 0) {
            if (type == 0) {
                dp[idx][value][type] = Math.max(dfw(idx - 1, value, type), dfw(idx - 1, value - pizzas[idx].price, 1) + pizzas[idx].value);
            } else {
                dp[idx][value][type] = Math.max(dfw(idx - 1, value, type), dfw(idx - 1, value, 0) + pizzas[idx].value);
            }
        }
        return dp[idx][value][type];
    }
    
    static class Pizza implements Comparable<Pizza> {
        int price;
        int value;
        
        public Pizza(int price, int value) {
            this.price = price;
            this.value = value;
        }
        
        public int compareTo(Pizza another) {
            return price - another.price;
        }
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}