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

void solve() {
    int n; cin >> n;
    vector<vector<int>> g(n);
    for (int i = 0; i < n - 1; i++) {
        int a, b; cin >> a >> b;
        a--, b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    vector<vector<int>> sz(n);
    vector<vector<int>> good(n);

    for (int i = 0; i < n; i++) {
        sz[i].resize(g[i].size(), -1);
        good[i].resize(g[i].size(), -1);
    }

    function<void(int, int)> dfs = [&](int v, int pt) {
        if (sz[v][pt] != -1) return;
        sz[v][pt] = 1;
        int u = g[v][pt];
        vector<int> sizes;
        bool isgood = 1;
        for (int i = 0; i < g[u].size(); i++) {
            if (g[u][i] == v) continue;
            if (sz[u][i] == -1)
                dfs(u, i);
            sz[v][pt] += sz[u][i];
//            maxsz = max(maxsz, sz[u][i]);
            sizes.push_back(sz[u][i]);
            isgood &= good[u][i];
        }
        sort(sizes.begin(), sizes.end());
        int cur = 1;
        for (int i = 0; i < sizes.size(); i++) {
            int ns = sizes[i];
            if (ns > cur) {
                isgood = 0;
                break;
            }
            cur += ns;
        }
        if (isgood) {
            good[v][pt] = 1;
        } else {
            good[v][pt] = 0;
        }
    };
    for (int i = 0; i < n; i++) {
        bool gg = 1;
        vector<int> sizes;
        for (int j = 0; j < g[i].size(); j++) {
            if (sz[i][j] == -1)
                dfs(i, j);
            if (!good[i][j]) gg = 0;
            sizes.push_back(sz[i][j]);
        }
        sort(sizes.begin(), sizes.end());
        int cur = 1;
        for (int i = 0; i < sizes.size(); i++) {
            int ns = sizes[i];
            if (ns > cur) {
                gg = 0;
                break;
            }
            cur += ns;
        }
        if (gg) {
            cout << "YES\n";
            return;
        }
    }
    cout << "NO\n";
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    solve();
    return 0;
}