#include<bits/stdc++.h>
#define maxn 200005
std::set<int> G[maxn];
std::queue<int> q1,q2;
bool vis[maxn];
bool deg2(int x) {
    if (vis[x]) return 0;
    if (G[x].size() > 2) return 0;
    for(auto i : G[x]) {
        if (G[i].size() == 1) {
            return 1;
        }
    }
    return 0;
}
void rmv(int u) {
    vis[u] = 1;
    for(auto i : G[u]) {
        G[i].erase(u);
        if (G[i].size() <= 1) {
            q1.push(i);
            if (G[i].size() > 0) {
                int v = *G[i].begin();
                if (deg2(v)) {
                    q2.push(v);
                }
            }
        }
        if (deg2(i)) {
            q2.push(i);
        }
    }
}
int main() {
    // freopen("in.txt","r",stdin);
    int n;
    std::cin >> n;
    for(int i = 1; i < n; i++) {
        int x,y;
        std::cin >> x >> y;
        G[x].insert(y);
        G[y].insert(x);
    }
    for(int i = 1; i <= n; i++) {
        if (G[i].size() <= 1) {
            q1.push(i);
        }
        if (deg2(i)){
            q2.push(i);
        }
    }
    int ans = 0;
    for(int cnt = 0;cnt < n;) {
        while(!q2.empty()) {
            int u = q2.front();q2.pop();
            if (!deg2(u)) continue;
            int v = -1;
            for(auto i : G[u]) {
                if (G[i].size() == 1) {
                    v = i;
                    break;
                }
            }
            rmv(v);
            rmv(u);
            cnt += 2;
            ans ++;
        }
        if (!q1.empty()) {
            int u = q1.front();
            q1.pop();
            if (vis[u]) continue;
            rmv(u);
            ans += 2;
            cnt++;
        }
    }
    std::cout << ans << std::endl;
}