#include <bits/stdc++.h>
#define LLI long long int
#define FOR(v, a, b) for(LLI v = (a); v < (b); ++v)
#define FORE(v, a, b) for(LLI v = (a); v <= (b); ++v)
#define REP(v, n) FOR(v, 0, n)
#define REPE(v, n) FORE(v, 0, n)
#define REV(v, a, b) for(LLI v = (a); v >= (b); --v)
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define ITR(it, c) for(auto it = (c).begin(); it != (c).end(); ++it)
#define RITR(it, c) for(auto it = (c).rbegin(); it != (c).rend(); ++it)
#define EXIST(c,x) ((c).find(x) != (c).end())
#define fst first
#define snd second
#define popcount __builtin_popcount
#define UNIQ(v) (v).erase(unique(ALL(v)), (v).end())
#define bit(i) (1LL<<(i))

#ifdef DEBUG
#include <misc/C++/Debug.cpp>
#else
#define dump(...) ((void)0)
#endif

#define gcd __gcd

using namespace std;
template <class T> constexpr T lcm(T m, T n){return m/gcd(m,n)*n;}

template <typename I> void join(ostream &ost, I s, I t, string d=" "){for(auto i=s; i!=t; ++i){if(i!=s)ost<<d; ost<<*i;}ost<<endl;}
template <typename T> istream& operator>>(istream &is, vector<T> &v){for(auto &a : v) is >> a; return is;}
template <typename T, typename U> bool chmin(T &a, const U &b){return (a>b ? a=b, true : false);}
template <typename T, typename U> bool chmax(T &a, const U &b){return (a<b ? a=b, true : false);}
template <typename T, size_t N, typename U> void fill_array(T (&a)[N], const U &v){fill((U*)a, (U*)(a+N), v);}

struct Init{
  Init(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(12);
    cerr << fixed << setprecision(12);
  }
}init;

int dp[5010][5010][2];

template <typename T>
void sort_with_ord(const std::vector<int> &ord, std::vector<T> &a){
  const int N = ord.size();
  std::vector<T> temp(N);
  for(int i = 0; i < N; ++i) temp[i] = a[ord[i]];
  std::swap(a, temp);
}


int main(){
  int N, K;
  while(cin >> N >> K){
    vector<int> P(N), D(N);
    REP(i,N) cin >> P[i] >> D[i];

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

    sort_with_ord(ord, P);
    sort_with_ord(ord, D);
    
    fill_array(dp, INT_MIN);

    dp[0][0][0] = 0;

    REP(i,N){
      FORE(j,0,K){
        chmax(dp[i+1][j][0], dp[i][j][0]);
        chmax(dp[i+1][j][1], dp[i][j][1]);
        
        if(j+P[i] <= K) chmax(dp[i+1][j+P[i]][1], dp[i][j][0] + D[i]);
        chmax(dp[i+1][j][0], dp[i][j][1] + D[i]);
      }
    }

    int ans = 0;
    FORE(j,0,K) chmax(ans, max(dp[N][j][0], dp[N][j][1]));

    cout << ans << endl;
  }

  return 0;
}