#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; }

constexpr long long MAX = 5100000;
constexpr long long INF = 1LL << 60;
constexpr int inf = 1 << 28;
//constexpr long long mod = 1000000007LL;
//constexpr long long mod = 998244353LL;

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

struct Pizza {
	ll p, d;
	Pizza(ll _p, ll _d) :p(_p), d(_d) {}
	bool operator<(const Pizza& pizza) {
		if (p == pizza.p) return d > pizza.d;
		return p > pizza.p;
	}
};

ll dp[5010][5010][2];
int main()
{
	/*
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	*/
	ll n, K; scanf("%lld %lld", &n, &K);
	for (int i = 0; i <= n; i++) for (int j = 0; j <= K; j++) for (int k = 0; k < 2; k++) dp[i][j][k] = -1;
	vector<Pizza> v; v.reserve(n);
	for (int i = 0; i < n; i++) {
		ll p, d; scanf("%lld %lld", &p, &d);
		v.emplace_back(p, d);
	}
	sort(v.begin(), v.end());
	dp[0][0][0] = 0;
	for (int i = 0; i < v.size(); i++) {
		for (int j = 0; j <= K; j++) {
			if (dp[i][j][0] != -1 && j + v[i].p <= K) chmax(dp[i + 1][j + v[i].p][1], dp[i][j][0] + v[i].d);
			chmax(dp[i + 1][j][0], dp[i][j][0]);
			chmax(dp[i + 1][j][1], dp[i][j][1]);
			if (dp[i][j][1] != -1) chmax(dp[i + 1][j][0], dp[i][j][1] + v[i].d);
		}
	}
	ll res = 0;
	for (ll i = 0; i <= K; i++) chmax(res, max(dp[n][i][0], dp[n][i][1]));
	cout << res << endl;
	return 0;
	/*
		おまじないを使ったらscanfとprintf関連注意！！！！！！！！！！！！
	*/
}