#include <bits/stdc++.h>
using namespace std;
int n, Ans;
int h[200001], nxt[400001], to[400001], tot;
inline void ins(int x, int y) {
  nxt[++tot] = h[x];
  to[tot] = y;
  h[x] = tot;
}
int f[200001], d[200001];
void DFS(int u, int fa) {
  f[u] = fa;
  for (int i = h[u]; i; i = nxt[i])
    if (to[i] != fa) {
      d[to[i]] = d[u] + 1;
      DFS(to[i], u);
    }
}
priority_queue<pair<int, int> > q;
bool vis[200001];
int main() {
  int x, y;
  scanf("%d", &n);
  for (int i = 2; i <= (n); ++i) scanf("%d%d", &x, &y), ins(x, y), ins(y, x);
  DFS(1, 0);
  for (int i = 1; i <= (n); ++i) q.push(pair<int, int>(d[i], i));
  int Ans = 0;
  while (!q.empty()) {
    while (!q.empty() && vis[q.top().second]) q.pop();
    if (q.empty()) break;
    if (q.top().first < 3) break;
    Ans++;
    int u = q.top().second;
    vis[f[u]] = 1;
    for (int i = h[f[u]]; i; i = nxt[i]) vis[to[i]] = 1;
  }
  printf("%d\n", Ans);
  return 0;
}
