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; }

string COLOR(string s = "") { return "\x1b[" ~ s ~ "m"; }

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 X = readInt;
      const Y = readInt;
      auto A = new long[N];
      auto B = new long[N];
      foreach (i; 0 .. N) {
        A[i] = readLong;
        B[i] = readLong;
      }
      
      auto ASum = new long[1 << N];
      auto BSum = new long[1 << N];
      foreach (i; 0 .. N) {
        foreach (h; 0 .. 1 << i) {
          ASum[h | 1 << i] = ASum[h] + A[i];
          BSum[h | 1 << i] = BSum[h] + B[i];
        }
      }
      auto fs = new long[1 << N];
      foreach (h; 0 .. 1 << N) if (ASum[h] <= Y) {
        fs[h] = BSum[h];
      }
      foreach (i; 0 .. N) {
        foreach (h; 0 .. 1 << N) if (!(h & 1 << i)) {
          chmax(fs[h | 1 << i], fs[h]);
        }
      }
      long ans;
      foreach (h; 0 .. 1 << N) if (ASum[h] <= X) {
        chmax(ans, BSum[h] + fs[((1 << N) - 1) - h]);
      }
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}