#include <bits/stdc++.h>

using namespace std;

using ll = long long;

constexpr ll INF = 1e16;

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n, K;
    cin >> n >> K;

    vector<int> ids(n), p(n), d(n);
    iota(ids.begin(), ids.end(), 0);

    for (int i = 0; i < n; ++i) {
        cin >> p[i] >> d[i];    
    }
    sort(ids.begin(), ids.end(), [&](int i1, int i2){
        return p[i1] > p[i2];
    });

    vector< vector<ll> > dp(2, vector<ll>(K + 1, -INF));
    dp[false][0] = 0;
    for (int i = 0; i < n; ++i) {
        int tar = ids[i];
        for (int j = K; j >= 0; --j) {
            // 無料
            if (dp[true][j] >= 0) {
                dp[false][j] = max(dp[false][j], dp[true][j] + d[tar]);
            }

            // 買う
            if (j >= p[tar] && dp[false][j - p[tar]] >= 0) {
                dp[true][j] = max(dp[true][j], dp[false][j - p[tar]] + d[tar]);
            }
        }
    }
    
    ll ans = 0;
    for (int i = 0; i <= K; ++i) {
        ans = max(ans, max(dp[false][i], dp[true][i]));
    }
    cout << ans << "\n";
    return 0;
}