#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

const long long MAX = 5100000;
const long long INF = 1LL << 60;
const long long mod = 1000000007LL;
//const long long mod = 998244353LL;

using namespace std;
typedef unsigned long long ull;
typedef long long ll;


struct Pizza {
	int p, d;
	Pizza(int _p, int _d) : p(_p), d(_d) {};
	Pizza() :p(0), d(0) {};
	bool operator < (const Pizza& e) {
		return p > e.p;
	}
};

Pizza pz[5010];
int dp[5010][5010][2];
int main()
{
	/*
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	*/
	ll N, K; scanf("%lld %lld", &N, &K);
	for (ll i = 0; i < N; i++) {
		ll p, d; scanf("%lld %lld", &p, &d);
		pz[i] = Pizza(p, d);
	}
	sort(pz, pz + N);
	for (ll i = 0; i <= N; i++)for (ll j = 0; j <= K; j++)for (ll k = 0; k < 2; k++) dp[i][j][k] = -1;
	dp[0][0][0] = 0;
	for (ll i = 0; i < N; i++) {
		for (ll j = 0; j <= K; j++) {
			if (dp[i][j][0] != -1) {
				chmax(dp[i + 1][j][0], dp[i][j][0]);
				if (j + pz[i].p <= K) {
					chmax(dp[i + 1][j + pz[i].p][1], dp[i][j][0] + pz[i].d);
				}
			}
			if (dp[i][j][1] != -1) {
				chmax(dp[i + 1][j][1], dp[i][j][1]);
				chmax(dp[i + 1][j][0], dp[i][j][1] + pz[i].d);
			}
		}
	}

	int res = 0;
	for (ll i = 0; i <= K; i++) for (ll j = 0; j < 2; j++) chmax(res, dp[N][i][j]);
	cout << res << endl;
	return 0;
}