#include<iostream>
#include<vector>
#include<algorithm>
#include<cstring>
using namespace std;

typedef pair<int,int> pii;
int dp[2][5001][5001];

int main(){
    memset(dp, -1, sizeof(dp));
    dp[0][0][0] = 0;
    int n, k;
    cin >> n >> k;
    vector<pii> v;
    for(int i = 0; i < n; i++){
        int p, d;
        cin >> p >> d;
        v.push_back({p, d});
    }
    sort(v.rbegin(), v.rend());
    for(int i = 0; i < n; i++){
        for(int j = k; j >= 0; j--){
            dp[1][i+1][j] = max(dp[1][i+1][j], dp[1][i][j]);
            dp[0][i+1][j] = max(dp[0][i+1][j], dp[0][i][j]);
            if(dp[0][i][j] != -1){
                if(j+v[i].first <= k)   dp[1][i+1][j+v[i].first] = max(dp[1][i+1][j+v[i].first], dp[0][i][j]+v[i].second);
            }
            if(dp[1][i][j] != -1){
                dp[0][i+1][j] = max(dp[0][i+1][j], dp[1][i][j]+v[i].second);
                dp[1][i+1][j] = max(dp[1][i+1][j], dp[1][i][j]);
            }
        }
    }
    int ans = 0;
    for(int i = 0; i <= k; i++){
        ans = max(ans, dp[0][n][i]);
        ans = max(ans, dp[1][n][i]);
    }
    cout << ans << endl;
    return 0;
}