#include <bits/stdc++.h>
std::vector<int> *adjacent_vertexes;
int n, ans, *max_length;
void pre_dfs(int u, int parent) {
  max_length[u] = 0;
  for (int v : adjacent_vertexes[u]) {
    if (v != parent) {
      pre_dfs(v, u);
      max_length[u] = std::max(max_length[v] + 1, max_length[u]);
    }
  }
  return;
}
void dfs(int u, int parent, int max_length_from_parent) {
  int first_max = 0, second_max = 0, first_max_rem;
  if (~parent) {
    first_max = max_length_from_parent;
    first_max_rem = parent;
  }
  for (int v : adjacent_vertexes[u]) {
    if (v != parent) {
      int tmp = max_length[v] + 1;
      if (tmp > first_max) {
        second_max = first_max;
        first_max = tmp;
        first_max_rem = v;
      } else if (tmp > second_max) {
        second_max = tmp;
      }
    }
  }
  ans += second_max + 1;
  for (int v : adjacent_vertexes[u]) {
    if (v != parent) {
      int max_length_from_u = v == first_max_rem ? second_max : first_max;
      ++ans;
      dfs(v, u, max_length_from_u + 1);
    }
  }
  return;
}
int main() {
  scanf("%d", &n);
  adjacent_vertexes = new std::vector<int>[n];
  max_length = new int[n];
  for (int i = 1; i < n; ++i) {
    int u, v;
    scanf("%d%d", &u, &v);
    adjacent_vertexes[--u].push_back(--v);
    adjacent_vertexes[v].push_back(u);
  }
  pre_dfs(0, -1);
  dfs(0, -1, 0);
  printf("%d\n", ans);
  return 0;
}
