#include <bits/stdc++.h>
using namespace std;
const int N = 1e5, K = 4;
vector<int> g[N];
set<int> s;
int a[N];
int get_index(const vector<int> x) {
  static map<vector<int>, int> m;
  static int cnt;
  if (m.find(x) == m.end()) m[x] = cnt++;
  return m[x];
}
void dfs_pre(int u, int fa) {
  vector<int> x;
  for (int v : g[u])
    if (v != fa) {
      dfs_pre(v, u);
      x.push_back(a[v]);
    }
  sort(x.begin(), x.end());
  a[u] = get_index(x);
}
void dfs(int u, int fa) {
  vector<int> x;
  if (g[u].size() < K) {
    for (int v : g[u]) x.push_back(a[v]);
    sort(x.begin(), x.end());
    s.insert(get_index(x));
  }
  sort(g[u].begin(), g[u].end(), [](int x, int y) { return a[x] < a[y]; });
  x.clear();
  for (int i = 1; i < g[u].size(); i++) x.push_back(a[g[u][i]]);
  int t = a[u];
  for (int i = 0; i < g[u].size(); i++) {
    if (g[u][i] != fa) {
      a[u] = get_index(x);
      dfs(g[u][i], u);
    }
    if (i < g[u].size() - 1) x[i] = a[g[u][i]];
  }
  a[u] = t;
}
int main() {
  ios::sync_with_stdio(false);
  int n;
  cin >> n;
  for (int i = 0; i < n - 1; i++) {
    int x, y;
    cin >> x >> y;
    x--, y--;
    g[x].push_back(y);
    g[y].push_back(x);
  }
  dfs_pre(0, -1);
  dfs(0, -1);
  cout << s.size() << endl;
}
