#include<bits/stdc++.h>
using namespace std;

#ifdef LOCAL
#include <debug_print.hpp>
#define OUT(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#define OUT(...) (static_cast<void>(0))
#endif

int main(){
  int N, M, Q;
  cin >> N >> M >> Q;
  assert(1 <= N && N <= 20);
  assert(1 <= M && M <= 1e9);
  assert(1 <= Q && Q <= 1e9);
  using ll = long long;
  vector<ll> A(N), B(N);
  for(int i = 0; i < N; i++){
    cin >> A[i] >> B[i];
    assert(1 <= A[i] && A[i] <= 1e9);
    assert(1 <= B[i] && B[i] <= 1e9);
  }

  vector<ll> dp(1 << N);
  for(int i = 0; i < 1 << N; i++){
    long long price = 0, value = 0;
    for(int j = 0; j < N; j++){
      if(i >> j & 1){
        price += A[j];
        value += B[j];
      }
    }
    if(price <= Q){
      dp[i] = value;
    } 
  }
  for(int i = 0; i < 1 << N; i++){
    for(int j = 0; j < N; j++){
      dp[i | 1 << j] = max(dp[i | 1 << j], dp[i]);
    }
  }
  long long ret = 0;
  for(int i = 0; i < 1 << N; i++){
    long long price = 0, value = 0;
    for(int j = 0; j < N; j++){
      if(i >> j & 1){
        price += A[j];
        value += B[j];
      }
    }
    if(price <= M){
      ret = max(ret, value + dp[i ^ ((1 << N) - 1)]);
    } 
  }
  cout << ret << endl;
}