#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
#include <queue>
using ll = long long;
using namespace std;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    vector<vector<int>> adj(n, vector<int>());
    for (int i = 0; i < n - 1; i++)
    {
        int v1, v2;
        cin >> v1 >> v2;
        v1--;
        v2--;
        adj[v1].push_back(v2);
        adj[v2].push_back(v1);
    }
    vector<int> lst;
    for (int i = 0; i < n; i++)
    {
        if (adj[i].size() >= 3)
        {
            lst.push_back(i);
        }
    }
    if (lst.size() >= 2)
    {
        cout << "No" << endl;
    }
    else if (lst.size() == 0)
    {
        cout << "Yes" << endl;
    }
    else {
        set<int> lens;
        queue<pair<int, pair<int, int>>> que;
        que.push(make_pair(lst[0], make_pair(-1, 0)));
        while (!que.empty())
        {
            auto data = que.front();
            que.pop();
            int v = data.first;
            int p = data.second.first;
            int d = data.second.second;
            bool isleaf = true;
            for (int w : adj[v])
            {
                if (w != p)
                {
                    isleaf = false;
                    que.push(make_pair(w, make_pair(v, d + 1)));
                }
            }
            if (isleaf)
            {
                lens.insert(d);
            }
        }
        cout << (lens.size() == 1 ? "Yes" : "No") << endl;
    }
}