#include <bits/stdc++.h>
using namespace std;


int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n;
    cin >> n;

    vector <vector <int>> adj(n);
    vector <int> degree(n), alive(n, 1);
    vector <int> elems_in_node(n, 1);

    for (int i = 1; i < n; i++) {
        int a, b;
        cin >> a >> b;
        a--, b--;
        adj[a].push_back(b);
        adj[b].push_back(a);
        degree[a]++, degree[b]++;
    }

    vector <int> q;
    for (int i = 0; i < n; i++)
        if (degree[i] == 1)
            q.push_back(i);


    for (int t = 0; t < (int)q.size(); t++) {
        int node = q[t];

        // node is a leaf, try to push up
        int next_node = -1;
        for (auto i : adj[node])
            if (alive[i])
                next_node = i;

        // try to push
        if (next_node != -1 && elems_in_node[next_node] >= elems_in_node[node]) {
            elems_in_node[next_node] += elems_in_node[node];
            elems_in_node[node] = 0;
            degree[next_node]--;
            if (degree[next_node] == 1)
                q.push_back(next_node);
        }

        // die
        alive[node] = 0;
    }

    int nr_non_0 = 0;
    for (int i = 0; i < n; i++)
        nr_non_0 += (elems_in_node[i] > 0);
    
    cout << (nr_non_0 == 1 ? "YES\n" : "NO\n");
}