#include <bits/stdc++.h>

#include <variant>

#define rep2(i, k, n) for (i64 i = (i64)(k); i < (i64)(n); i++)
#define rep(i, n) rep2(i, 0, n)
#define all(x) begin(x), end(x)
#ifdef ENV_LOCAL
#define dump \
  if (1) cerr
#else
#define dump \
  if (0) cerr
#endif

using namespace std;
using namespace std::string_literals;

using i32 = int32_t;
using i64 = int64_t;
using f64 = double;
using f80 = long double;
using vi32 = vector<i32>;
using vi64 = vector<i64>;

// using namespace harudake;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  i64 n;
  cin >> n;
  vector<tuple<i64, i64, i64>> vp;
  rep(i, n) {
    i64 x, y, t;
    cin >> x >> y >> t;
    vp.emplace_back(x, y, t);
  }
  vector<bool> vis(n, false);
  i64 INF = 1e18;
  vi64 mins(n, INF);
  mins[0] = 0;
  rep(i, n) {
    i64 idx = -1;
    i64 mn = INF;
    rep(j, n) {
      if (vis[j]) continue;
      if (mins[j] < mn) {
        mn = mins[j];
        idx = j;
      }
    }
    vis[idx] = true;
    auto [x, y, t] = vp[idx];
    rep(j, n) {
      auto d = [&] {
        auto [xj, yj, tj] = vp[j];
        if (t != tj) {
          i64 rsq1 = x * x + y * y;
          i64 rsq2 = xj * xj + yj * yj;
          i64 val = ceil(rsq1 + rsq2 - 2 * sqrt(rsq1 * rsq2));
          return val;
        } else {
          i64 xd = x - xj;
          i64 yd = y - yj;
          return xd * xd + yd * yd;
        }
      }();
      if (mins[j] > max(mins[idx], d)) {
        mins[j] = max(mins[idx], d);
      }
    }
  }
  cout << mins.back() << endl;
  return 0;
}