#include <bits/stdc++.h>
using namespace std;
#define all(v) (v).begin(),(v).end()
#define pb(a) push_back(a)
#define rep(i, n) for(int i=0;i<n;i++)
#define foa(e, v) for(auto&& e : v)
using ll = long long;
const ll MOD7 = 1000000007, MOD998 = 998244353, INF = (1LL << 60);
#define dout(a) cout<<fixed<<setprecision(10)<<a<<endl;

void chmax(ll &a, ll b) { a = max(a, b); }
vector<ll> solve(ll n, ll x, vector<ll> &w, vector<ll> &v) {
    ll mask = 1LL << n;
    vector<ll> dp(mask, 0);
    rep(bit, mask) {
        ll sumx = 0, sum = 0;
        rep(i, n) if(bit >> i & 1) {
            sumx += w[i];
            sum += v[i];
        }
        if(sumx <= x) dp[bit] = sum;
    }
    rep(bit, mask) {
        rep(i, n) if(bit >> i & 1) {
            chmax(dp[bit], dp[bit ^ (1 << i)]);
        }
    }
    return dp;
}
int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll n, m, q;
    cin >> n >> m >> q;
    vector<ll> a(n), b(n);
    rep(i, n) cin >> a[i] >> b[i];
    auto dp1 = solve(n, m, a, b);
    auto dp2 = solve(n, q, a, b);
    ll ans = 0;
    ll mask = (1LL << n);
    rep(i, mask) chmax(ans, dp1[i] + dp2[(mask - 1) ^ i]);
    cout << ans << endl;
    return 0;
}