#include <bits/stdc++.h>
using namespace std;

const int MAX = 5010;
int dp[MAX][MAX][2];
int main() {
	int N, K; cin >> N >> K;
	pair<int, int> p[N];
	for(int i = 0; i < N; ++i) {
		cin >> p[i].first >> p[i].second;
	}
	sort(p, p + N);
	reverse(p, p + N);
	for(int i = 0; i < MAX; ++i) {
		for(int j = 0; j < MAX; ++j) {
			for(int k = 0; k < 2; ++k) {
				dp[i][j][k] = -1e9;
			}
		}
	}
	dp[0][0][0] = 0;
	for(int i = 1; i <= N; ++i) {
		int cos, val;
		tie(cos, val) = p[i - 1];
		for(int j = 0; j <= K; ++j) {
			dp[i][j][0] = dp[i - 1][j][0];
			dp[i][j][0] = max(dp[i][j][0], dp[i - 1][j][1] + val);
			dp[i][j][1] = dp[i - 1][j][1];
			if(j - cos >= 0) {
				dp[i][j][1] = max(dp[i][j][1], dp[i - 1][j - cos][0] + val);
			}
		}
	}
	int ans = 0;
	for(int j = 0; j <= K; ++j) {
		for(int k = 0; k < 2; ++k) {
			ans = max(ans, dp[N][j][k]);
		}
	}
	cout << ans << '\n';
	return 0;
}