#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

struct Edge {
    int from, to, weight;
};

vector<vector<int>> adj;
vector<Edge> edges;
int n;

int findRoot(int x, vector<int>& parent) {
    if (parent[x] == x) return x;
    return findRoot(parent[x], parent);
}

void unionSets(int x, int y, vector<int>& parent) {
    int rootX = findRoot(x, parent);
    int rootY = findRoot(y, parent);
    if (rootX != rootY) {
        parent[rootY] = rootX;
    }
}

int kruskalMST() {
    vector<int> parent(n + 1);
    for (int i = 1; i <= n; ++i) {
        parent[i] = i;
    }

    sort(edges.begin(), edges.end(), [](const Edge& a, const Edge& b) {
        return a.weight < b.weight;
    });

    int mstCost = 0;
    for (const auto& edge : edges) {
        int x = edge.from, y = edge.to;
        if (findRoot(x, parent) != findRoot(y, parent)) {
            unionSets(x, y, parent);
            mstCost += edge.weight;
        }
    }

    return mstCost;
}

int main() {
    cin >> n;
    adj.resize(n + 1);
    edges.resize(n - 1);

    for (int i = 0; i < n - 1; ++i) {
        int x, y;
        cin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
        edges[i] = {x, y, 1};
    }

    int minCost = kruskalMST();
    cout << minCost << endl;

    return 0;
}