import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }




void main() {
  try {
    for (; ; ) {
      const N = readInt();
      const K = readInt();
      auto A = new Tuple!(int, "p", int, "d")[N];
      foreach (i; 0 .. N) {
        A[i].p = readInt();
        A[i].d = readInt();
      }
      A.sort!"a.p < b.p";
      
      auto dp0 = new int[][](N + 1, K + 1);
      auto dp1 = new int[][](N + 1, K + 1);
      foreach (i; 0 .. N + 1) {
        dp0[i][] = -1;
        dp1[i][] = -1;
      }
      dp0[0][0] = 0;
      dp1[0][0] = 0;
      foreach (i; 0 .. N) {
        foreach (x; 0 .. K + 1) {
          if (dp0[i][x] >= 0) {
            chmax(dp0[i + 1][x], dp0[i][x]);
            chmax(dp1[i + 1][x], dp0[i][x] + A[i].d);
          }
        }
        foreach (x; 0 .. K + 1) {
          if (dp1[i][x] >= 0) {
            chmax(dp1[i + 1][x], dp1[i][x]);
            if (x + A[i].p <= K) {
              chmax(dp0[i + 1][x + A[i].p], dp1[i][x] + A[i].d);
            }
          }
        }
      }
      int ans = -1;
      foreach (x; 0 .. K + 1) {
        chmax(ans, dp0[N][x]);
      }
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}