#include <cmath>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <functional>
#include <queue>
#include <iostream>
#include <string.h>
#include <iomanip>
#include <algorithm>
#include <functional>
#include <cstdint>
#include <climits>
#include <unordered_set>
#include <unordered_map>
#include <sstream>
#include <stack>

using namespace std;

typedef long long int ll;
typedef pair<char,char> pcc;
typedef pair<ll,ll> P;
typedef tuple<ll,ll,ll> t3;

#define rep(i,a) for(ll i = 0;i < a;i++)

template <class T>
void cmax(T& a, const T b){a=max(a,b);}

const ll mod = 1e9+7;

int main(void) {
    ll n,k;
    cin >> n >> k;
    vector<P> vs(n);
    rep(i,n){
        cin >> vs[i].first >> vs[i].second;
    }
    sort(vs.begin(),vs.end(),[&](P a, P b){
        if(a.first == b.first){
            return a.second > b.second;
        }
        return a.first > b.first;
    });
    vector<vector<vector<ll>>> dp(2, vector<vector<ll>>(k+10, vector<ll>(2,0)));
    rep(i,n){
        auto p = vs[i].first;
        auto d = vs[i].second;
        for(int j = 0;j <= k;j++){
            cmax(dp[1][j][0],dp[0][j][0]);
            cmax(dp[1][j][1],dp[0][j][1]);
            if(dp[0][j][1] != 0){
                cmax(dp[1][j][0],dp[0][j][1] + d);
            }
        }
        for(int j = 0;j+p <= k;j++){
            cmax(dp[1][j+p][1], dp[0][j][0] + d);
        }
        swap(dp[0], dp[1]);
    }
    ll m = 0;
    rep(j,k+1){
        cmax(m, dp[0][j][0]);
        cmax(m, dp[0][j][1]);
    }
    cout << m << endl;
    return 0;
}