#include <iostream>
#include <vector>

using namespace std;

class Tree {
public:
    int n;
    vector<vector<int>> adj;

    Tree(int n) : n(n), adj(n + 1) {}

    void addEdge(int u, int v) {
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    int dfs(int u, int parent, vector<int>& subtreeSize) {
        int size = 1;
        for (int v : adj[u]) {
            if (v!= parent) {
                size += dfs(v, u, subtreeSize);
            }
        }
        subtreeSize[u] = size;
        return size;
    }

    int findCentroid() {
        vector<int> subtreeSize(n + 1);
        dfs(1, -1, subtreeSize);

        int centroid = -1;
        int minSize = n;
        function<void(int, int)> find = [&](int u, int parent) {
            bool isCentroid = true;
            int maxSubtree = 0;
            for (int v : adj[u]) {
                if (v!= parent) {
                    if (subtreeSize[v] > n / 2) {
                        isCentroid = false;
                    }
                    maxSubtree = max(maxSubtree, subtreeSize[v]);
                }
            }
            if (n - subtreeSize[u] > n / 2) {
                isCentroid = false;
            }
            if (isCentroid && maxSubtree < minSize) {
                centroid = u;
                minSize = maxSubtree;
            }
            for (int v : adj[u]) {
                if (v!= parent) {
                    find(v, u);
                }
            }
        };

        find(1, -1);
        return centroid;
    }
};

int solve(Tree& tree) {
    int centroid = tree.findCentroid();
    return tree.n - 1;
}
int main() {
    int n;
    cin >> n;
    Tree tree(n);
    for (int i = 0; i < n - 1; ++i) {
        int u, v;
        cin >> u >> v;
        tree.addEdge(u, v);
    }
    cout << solve(tree) << endl;
    return 0;
}

answer.code:9:22: error: '>>' should be '> >' within a nested template argument list
     vector<vector<int>> adj;\x0d
                      ^
answer.code: In member function 'int Tree::dfs(int, int, std::vector<int>&)':
answer.code:20:22: error: range-based 'for' loops are not allowed in C++98 mode
         for (int v : adj[u]) {\x0d
                      ^
answer.code: In member function 'int Tree::findCentroid()':
answer.code:35:9: error: 'function' was not declared in this scope
         function<...