#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;
using mint = modint998244353;

int main() {
  int N, V, C; cin >> N >> V >> C;
  vector<int> v(N), w(N);
  for (int i = 0; i < N; i++) cin >> v[i] >> w[i];
  vector<int> dp(V + 1, -1e9);
  dp[0] = 0;
  for (int i = 0; i < N; i++) {
    for (int j = V; j >= 0; j--) {
      if (j + v[i] > V) continue;
      dp[j + v[i]] = max(dp[j + v[i]], dp[j] + w[i] + C);
    }
    for (int j = 0; j + v[i] <= V; j++) {
      dp[j + v[i]] = max(dp[j + v[i]], dp[j] + w[i]);
    }
  }
  int ans = 0;
  for (int i = 0; i <= V; i++) ans = max(ans, dp[i]);
  cout << ans << endl;
  return 0;
}