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

#define rep(i,a,b) for (int i = (a); i < (b);++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

signed main()
{
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    int n;
    cin >> n;
    vector<vector<int>> adj(n + 1);
    for (int i = 0; i + 1 < n; ++i)
    {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    vector<int> sizes(n + 1);
    vector<bool> dp(n + 1);
    vector<vector<int>> child(n + 1);
    auto dfs1 = [&adj, &dp, &child, &sizes](auto&& self, int v, int p) -> void
    {
        sizes[v] = 1;
        for (int i : adj[v])
        {
            if (i == p)
                continue;
            child[v].push_back(i);
            self(self, i, v);
            sizes[v] += sizes[i];
        }
        sort(child[v].begin(), child[v].end(), [&sizes](int a, int b){ return sizes[a] < sizes[b]; });
        int cnt = 1;
        dp[v] = true;
        for (int i : child[v]) {
            if (cnt < sizes[i] || !dp[i]) {
                dp[v] = false;
                break;
            }
            cnt += sizes[i];
        }
    };
    dfs1(dfs1, 1, 0);
    auto dfs2 = [&adj, &dp, &child, &sizes](auto&& self, int v, int p) -> bool
    {
        if (p != 0) {
            child[v].push_back(p);
            sizes[v] += sizes[p];
        }
        sort(child[v].begin(), child[v].end(), [&sizes](int a, int b){ return sizes[a] < sizes[b]; });
        bool res = true;
        int baddp = -1;
        int cnt = 1;
        int first = -1;
        for (int i : child[v])
        {
            if (first == -1 && cnt < sizes[i])
                first = i;
            if (!dp[i] || cnt < sizes[i])
            {
                res = false;
            }
            if (!dp[i])
            {
                if (baddp != -1)
                {
                    return false;
                }
                baddp = i;
            }
            cnt += sizes[i];
        }
        if (res)
            return true;
        if (baddp != -1) {
            vector<int> good;
            for (int i: child[v])
                if (i != baddp)
                    good.push_back(i);
            sort(good.begin(), good.end(), [&sizes](int a, int b) { return sizes[a] < sizes[b]; });
            cnt = 1;
            res = true;
            for (int i: good) {
                if (cnt < sizes[i]) {
                    res = false;
                    break;
                }
                cnt += sizes[i];
            }
            if (!res)
                return false;
            dp[v] = true;
            sizes[v] -= sizes[baddp];
            return self(self, baddp, v);
        }
        if (first == -1 || first == p)
            return false;
        vector<int> good;
        for (int i: child[v])
            if (i != first)
                good.push_back(i);
        sort(good.begin(), good.end(), [&sizes](int a, int b) { return sizes[a] < sizes[b]; });
        cnt = 1;
        res = true;
        for (int i: good) {
            if (cnt < sizes[i]) {
                res = false;
                break;
            }
            cnt += sizes[i];
        }
        if (!res)
            return false;
        dp[v] = true;
        sizes[v] -= sizes[first];
        return self(self, first, v);
    };
    if (dfs2(dfs2, 1, 0))
    {
        cout << "YES\n";
    }
    else
        cout << "NO\n";
    return 0;
}