func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 1e5 + 5;   vector<int> ed[N], leaves;   int n, root = -1;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     cin >> n;     for (int i = 1; i < n; i++) {       int u, v;       cin >> u >> v;       ed[u].push_back(v);       ed[v].push_back(u);     }     for (int i = 1; i <= n; i++) {       if (ed[i].size() > 2) {         if (root != -1) {           cout <<  No n ;           return 0;         }         root = i;       }       if (ed[i].size() == 1) leaves.push_back(i);     }     if (root == -1)       cout <<  Yes n             <<  1 n             << leaves[0] <<     << leaves.back() <<   n ;     else {       cout <<  Yes n ;       cout << leaves.size() <<   n ;       for (auto i : leaves) cout << root <<     << i <<   n ;     }   }   