#include <bits/stdc++.h>

using namespace std;

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

    int n;
    cin >> n;

    vector<vector<int>> graph(n + 1);

    for(int i = 1; i < n; i++) {
        int u, v;
        cin >> u >> v;

        graph[u].push_back(v);
        graph[v].push_back(u);
    }

    vector<int> weight(n + 1, 0);
    vector<int> father(n + 1, 0);

    function<void(int, int)> dfs = [&](int nod, int tata) {
        weight[nod] = 1;
        father[nod] = tata;
        for(auto it:graph[nod]) {
            if(it == tata) {
                continue;
            }
            dfs(it, nod);
            weight[nod] += weight[it];
        }
    };

    dfs(1, 0);

    int curr = 1;

    while(true) {
        int idx = -1;
        for(auto it:graph[curr]) {
            if(it == father[curr]) {
                continue;
            }
            if(idx == -1 || weight[idx] < weight[it]) {
                idx = it;
            }
        }
        if(idx == -1 || weight[idx] * 2 <= n) {
            break;
        }
        curr = idx;
    }

    vector<int> local_weights;
    function<bool(int, int)> check = [&](int nod, int tata) {
        weight[nod] = 1;
        father[nod] = tata;

        for(auto it:graph[nod]) {
            if(it == tata) {
                continue;
            }
            if(!check(it, nod)) {
                return false;
            }
            weight[nod] += weight[it];
        }

        local_weights.clear();
        for(auto it: graph[nod]) {
            if(it == tata) {
                continue;
            }
            local_weights.push_back(weight[it]);
        }
        sort(local_weights.begin(), local_weights.end());
        int curr_weight = 1;

        for(auto it: local_weights) {
            if(curr_weight < it) {
                return false;
            }
            curr_weight += it;
        }
        return true;
    };

    cout << (check(curr, 0) ? "YES":"NO");



    return 0;
}