#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
istream &operator>>(istream &is, modint &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint &a) { return os << a.val(); }
istream &operator>>(istream &is, modint998244353 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint998244353 &a) { return os << a.val(); }
istream &operator>>(istream &is, modint1000000007 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint1000000007 &a) { return os << a.val(); } 

typedef long long ll;
typedef vector<vector<int>> Graph;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define FOR(i,l,r) for (int i = l;i < (int)(r); i++)
#define rep(i,n) for (int i = 0;i < (int)(n); i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define my_sort(x) sort(x.begin(), x.end())
#define my_max(x) *max_element(all(x))
#define my_min(x) *min_element(all(x))
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const int INF = (1<<30) - 1;
const ll LINF = (1LL<<60) - 1;
const int MOD = 998244353;
const int MOD2 = 1e9+7;
const double PI = acos(-1);
vector<int> di = {1,0,-1,0};
vector<int> dj = {0,1,0,-1};

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

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    int N; cin >> N;
    int L = 1 << N;
    int mask = L - 1;

    ll M, Q; cin >> M >> Q;
    vector<ll> A(N), B(N);
    rep(i,N) cin >> A[i] >> B[i];

    // dp1[S] ... Sの部分集合で1日目の最大値
    vector<ll> dp1(L);
    rep(s,L){
        ll acc_a = 0, acc_b = 0;
        rep(bit,N)if((s>>bit)&1){
            acc_a += A[bit];
            acc_b += B[bit];
        }
        if(acc_a <= M) dp1[s] = acc_b;
    }
    rep(s,L)rep(bit,N)if((~s>>bit)&1)chmax(dp1[s|(1<<bit)], dp1[s]);

    // dp2[S] ... Sの部分集合で2日目の最大値
    vector<ll> dp2(L);
    rep(s,L){
        ll acc_a = 0, acc_b = 0;
        rep(bit,N)if((s>>bit)&1){
            acc_a += A[bit];
            acc_b += B[bit];
        }
        if(acc_a <= Q) dp2[s] = acc_b;
    }
    rep(s,L)rep(bit,N)if((~s>>bit)&1)chmax(dp2[s|(1<<bit)], dp2[s]);

    ll ans = 0;
    rep(s,L)chmax(ans, dp1[s] + dp2[mask ^ s]);
    cout << ans << endl;
}