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

typedef long long ll;

void solve() {
    int N;
    cin >> N;

    vector<vector<int>> tree(N);
    vector<int> deg(N);
    for (int i = 0; i < N - 1; i++) {
        int u, v;
        cin >> u >> v;
        u--, v--;
        tree[u].push_back(v);
        tree[v].push_back(u);
        deg[u]++;
        deg[v]++;
    }

    priority_queue<pair<int, int>> Q;
    for (int i = 0; i < N; i++) {
        if (deg[i] == 1) {
            Q.emplace(-deg[i], i);
        }
    }

    vector<vector<int>> moves(N);
    vector<int> cnt(N, 1);
    for (int i = 0; i < N; i++) {
        int u = Q.top().second;
        Q.pop();

        sort(moves[u].begin(), moves[u].end());
        for (int c : moves[u]) {
            // cout << "cnt[" << u+1 << "] += " << c << endl;
            if (c > cnt[u]) {
                cout << "NO\n";
                return;
            }
            cnt[u] += c;
        }

        for (int v : tree[u]) {
            if (cnt[v] != 0) {
                moves[v].push_back(cnt[u]);
                cnt[u] = 0;
                deg[v]--;
                // cout << u+1 << " -> " << v+1 << " " << deg[v] << endl;
                if (deg[v] == 1) {
                    Q.emplace(-accumulate(moves[v].begin(), moves[v].end(), 1ll), v);
                }
            }
        }
    }

    cout << "YES\n";
}

int main() {
    ios::sync_with_stdio(false);

    int T = 1;
    // cin >> T;

    for (int i = 1; i <= T; i++) {
        solve();
    }

    return 0;
}