#include <bits/stdc++.h>
using namespace std;
// #include <atcoder/all>
// using namespace atcoder;
#define rep(i, l, r) for (auto i = (l); i < (r); i++)
#define all(a) a.begin(), a.end()
#define chmin(dest, src) if ((dest) > (src)) dest = (src)
#define chmax(dest, src) if ((dest) < (src)) dest = (src)
using ll = int;
using i64 = long long;
using i32 = long;
using u64 = unsigned long long;
using u32 = unsigned long;

int main() {
    int N, V, C; cin >> N >> V >> C;
    
    vector<int> dp(V + 1, 0);
    rep (i, 0, N) {
        int v, w; cin >> v >> w;
        vector<int> dp2(V + 1, 0);

        rep (i, v, V + 1) {
            chmax(dp2[i], dp[i - v] + C + w);
            chmax(dp2[i], dp2[i - v] + w);
        }
        rep (i, 0, V + 1) {
            chmax(dp[i], dp2[i]);
        }
    }

    int ans = 0;
    rep (i, 0, V + 1) chmax(ans, dp[i]);

    cout << ans << endl;

  return 0;
}