#include <bits/stdc++.h>   using namespace std;   void solve() {     int n, cnt = 0;     cin >> n;     vector<vector<int>> adj(n);     vector<int> deg(n);     for (int i = 0; i < n - 1; i++) {       int x, y;       cin >> x >> y;       x--, y--;       adj[x].push_back(y);       adj[y].push_back(x);       deg[x]++, deg[y]++;     }     for (int i = 0; i < n; i++)       if (deg[i] == 1)         cnt++;       else if (deg[i] == 2) {         cnt = 0;         break;       }     if ((long long)cnt * (cnt - 1) >= 2 * (n - 1))       cout <<  YES  <<   n ;     else       cout <<  NO  <<   n ;   }   int main() {     ios_base ::sync_with_stdio(false);     cin.tie(nullptr);     cout.tie(nullptr);     solve();     return 0;   }   