func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long P = 1e9 + 7;   const int N = 2e5 + 5;   const int inf = 0x3f3f3f3f;   const double pi = acos(-1);   mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());   int n, x, y, a[2];   vector<int> g[N];   void dfs(int x, int fa, int grp) {     a[grp]++;     for (auto u : g[x])       if (u != fa) dfs(u, x, 1 - grp);   }   int main() {     scanf( %d , &n);     for (int i = (1); i <= (n - 1); ++i) {       scanf( %d%d , &x, &y);       g[x].push_back(y), g[y].push_back(x);     }     dfs(1, 0, 0);     cout << min(a[0], a[1]) - 1 << endl;     return 0;   }   