#pragma gcc target("avx2")
#pragma gcc optimize("o3")
#pragma gcc optimize("unroll-loops")
//#pragma warning(disable : 4996)

//#define ATCODER
#ifdef ATCODER
#include <atcoder/all>
using namespace atcoder;
#endif

#include <limits.h>
#include <math.h>
#include <time.h>

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <complex>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

#if defined(LOCAL) || defined(_MSC_VER)
void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << " " << to_string(H);
    debug_out(T...);
}

#define DEBUG(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define DEBUG(...) 42
#endif

#ifdef _MSC_VER
#include <intrin.h>

#include "stdafx.h"
#define __builtin_popcount __popcnt
#define __builtin_popcountll __popcnt64
#endif

#define ll long long
#define REP(i, n) for (ll i = 0; i < (n); ++i)
#define REPR(i, n) for (ll i = (n)-1; i >= 0; --i)
#define FOR(i, m, n) for (ll i = (m); i < (n); ++i)
#define VSORT(v) sort(v.begin(), v.end());
#define VREVERSE(v) reverse(v.begin(), v.end())
#define print(x) cout << (x) << '\n'
#define spa << " " <<
#define lb(v, n) lower_bound(v.begin(), v.end(), (n))
#define ub(v, n) upper_bound(v.begin(), v.end(), (n))
#define int long long
//#define double long double
#define all(x) (x).begin(), (x).end()
#define print_space(v) \
    REP(i, v.size()) cout << v[i] << " \n"[i == (int)v.size() - 1]
template <typename T1, typename T2>
inline bool chmin(T1& a, T2 b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
inline bool chmax(T1& a, T2 b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
std::random_device rd;
std::mt19937 mt(rd());
constexpr ll MOD = 998244353;
constexpr int MAX = 400040;
const double pi = acos(-1);
constexpr long double EPS = 1e-9;
const int dx[4] = { 0, 0, -1, 1 }, dy[4] = { -1, 1, 0, 0 };
using ld = long double;



int dp[5050][5050][2];
const ll INF = 1e18;
void solve() {
    int N, K; cin >> N >> K;
    vector<int>P(N), D(N);
    REP(i, N)cin >> P[i] >> D[i];
    vector<pii>v(N);
    REP(i, N)v[i] = { P[i],D[i] };
    VSORT(v);
    VREVERSE(v);
    REP(i, N + 1)REP(j, K + 1)REP(f, 2)dp[i][j][f] = -INF;
    dp[0][0][0] = 0;
    REP(i, N)REP(j, K + 1)REP(f, 2) {
        chmax(dp[i + 1][j][f], dp[i][j][f]);
        if (f) {
            chmax(dp[i + 1][j][0], dp[i][j][f] + v[i].second);
        }
        else {
            if (j + v[i].first <= K)chmax(dp[i + 1][j + v[i].first][1], dp[i][j][f] + v[i].second);
        }
    }
    int ans = 0;
    REP(j, K + 1)REP(f, 2)chmax(ans, dp[N][j][f]);
    print(ans);
}

signed main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    // int q; cin >> q;
    // while (q--)
    solve();
}