#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
	int N;ll M, Q;cin >> N >> M >> Q;
	vector<ll> A(N), B(N);
	for (int i = 0;i < N;i++) cin >> A[i] >> B[i];
	vector<vector<ll>> dp(1 << N, vector<ll>(N + 1, 0));
	for (int bit = 0;bit < (1 << N);bit++) {
		ll m = 0;ll v = 0;
		for (int i = 0;i < N;i++) if (bit & (1 << i)) m += A[i],v += B[i];
		if (m <= Q) dp[bit][0] = v;
	}
	for (int i = 0;i < N;i++) for (int bit = 0;bit < (1 << N);bit++) {
		if (bit & (1 << i)) {
			dp[bit][i + 1] = max(dp[bit][i], dp[bit & ~(1 << i)][i]);
		} else {
			dp[bit][i + 1] = dp[bit][i];
		}
	}
	ll ans = 0;
	for (int bit = 0;bit < (1 << N);bit++) {
		ll m = 0;ll v = 0;
		for (int i = 0;i < N;i++) if (bit & (1 << i)) m += A[i],v += B[i];
		if (m > M) continue;
		int tbit = ((1 << N) - 1) ^ bit;
		ans = max(ans, dp[tbit][N] + v);
	}
	cout << ans << endl;
}