#include <bits/stdc++.h>

#define int long long
#define fr first
#define se second

constexpr int N = 1e5 + 6;

void solve() {
  int n, W, k;
  std::cin >> n >> W >> k;  
  std::vector<std::pair<int, int>> v(n + 1, std::make_pair(0, 0));
  std::vector<int> suf(n + 2, 0);
  for (int i = 1; i <= n; ++i) {
    std::cin >> v[i].fr >> v[i].se;
  }
  std::sort(v.begin(), v.end());
  int sum = 0;
  std::priority_queue<int> pq;
  for (int i = n; i; --i) {
    pq.emplace(-v[i].se);
    sum += v[i].se;
    if ((int)pq.size() > k) {
      sum += pq.top();
      pq.pop();
    }
    suf[i] = sum;
  }
  std::vector<int> dp(W + 1, 0);
  int mx = -1;
  for (int i = 1; i <= n; ++i) {
    for (int j = W; j >= v[i].fr; --j) {
      dp[j] = std::max(dp[j], dp[j - v[i].fr] + v[i].se);
      mx = std::max(mx, dp[j] + suf[i + 1]);
    }
  }
  std::cout << mx << "\n";
}

int32_t main() {
  std::ios::sync_with_stdio(0);
  std::cin.tie(0), std::cout.tie(0);
  // freopen("knapsack.in", "r", stdin);
  // freopen("knapsack.out", "w", stdout);

  int t;
  // std::cin >> t;
  t = 1;

  while (t--) {
    solve();
  }

  return 0;
}