#include <bits/stdc++.h>

using namespace std;

constexpr std::int32_t INF = 1 << 30;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int N, V, C;
  cin >> N >> V >> C;
  vector<int> A(N), B(N);
  for (int i = 0; i < N; i++) {
    cin >> A[i] >> B[i];
  }
  vector<int> dp(V + 1, -INF);
  dp[0] = 0;
  for (int i = 0; i < N; i++) {
    vector<int> dq(V + 1, -INF);
    for (int j = 0; j + A[i] <= V; j++) {
      dq[j + A[i]] = max(dq[j + A[i]], dp[j] + B[i] + C);
      dq[j + A[i]] = max(dq[j + A[i]], dq[j] + B[i]);
    }
    for (int j = 0; j <= V; j++) {
      dp[j] = max(dp[j], dq[j]);
    }
  }
  cout << *ranges::max_element(dp) << '\n';
  return 0;
}