#pragma GCC target("avx2,avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<long long, long long>;
#define rep(i, n) for(int i = 0; i < (n); ++i)
#define all(x) (x).begin(),(x).end()
constexpr char ln = '\n';
constexpr long long MOD = 1000000007;
//constexpr long long MOD = 998244353;
template<class T1, class T2> inline bool chmax(T1 &a, T2 b) {if (a < b) {a = b; return true;} return false;}
template<class T1, class T2> inline bool chmin(T1 &a, T2 b) {if (a > b) {a = b; return true;} return false;}
inline int topbit(int x) {return x == 0 ? -1 : 31-__builtin_clz(x);}
inline int topbit(long long x) {return x == 0 ? -1 : 63-__builtin_clzll(x);}
inline int botbit(int x) {return x == 0 ? 32 : __builtin_ctz(x);}
inline int botbit(long long x) {return x == 0 ? 64 : __builtin_ctzll(x);}
inline int popcount(int x) {return __builtin_popcount(x);}
inline int popcount(long long x) {return __builtin_popcountll(x);}
void print() {cout << "\n";}
template<class T, class... Args>
void print(const T &x, const Args &... args) {
    cout << x << " ";
    print(args...);
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////

int dp[5050][5050][2];
int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);
    int N,K; cin >> N >> K;
    vector<int> P(N),D(N);
    rep(i,N) cin >> P[i] >> D[i];

    vector<int> idx(N);
    iota(all(idx),0);
    sort(all(idx),[&](int i, int j){return P[i]>P[j];});

    rep(i,N+1) rep(j,K+1) rep(k,2) dp[i][j][k] = -1e9;
    dp[0][0][0] = 0;
    rep(i,N) {
        int u = idx[i];
        rep(j,K+1) {
            rep(k,2) {
                if (dp[i][j][k]==-1e9) continue;
                chmax(dp[i+1][j][k],dp[i][j][k]);
                if (!k and j+P[u]<=K) chmax(dp[i+1][j+P[u]][k^1],dp[i][j][k]+D[u]);
                if (k) chmax(dp[i+1][j][k^1],dp[i][j][k]+D[u]);
            }
        }
    }

    int ans = 0;
    rep(j,K+1) rep(k,2) chmax(ans,dp[N][j][k]);

    cout << ans << ln; 
}