#include <bits/stdc++.h>

using namespace std;
using ll = long long;



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

    int n;
    cin >> n;
    vector<set<int>> adj(n);
    for (int i = 0; i < n - 1; i++) {
        int a;
        int b;
        cin >> a >> b;
        a--;
        b--;
        adj[a].insert(b);
        adj[b].insert(a);
    }
    if (n == 1) {
        cout << "YES\n";
        return;
    }

    set<array<int, 2>> leafs;
    for (int i = 0; i < n; i++) {
        if (adj[i].size() == 1) {
            leafs.insert({1, i});
        }
    }

    map<int, int> in;
    for (int i = 0; i < n; i++) {
        in[i] = 1;
    }
    while (leafs.size() > 1) {
        int cur = (*leafs.begin())[1];
        // cout << cur << " " << in[cur] << endl;
        int next = *adj[cur].begin();
        if (in[cur] > in[next])
            break;
        leafs.erase(leafs.begin());
        in[next] += in[cur];
        adj[next].erase(cur);
        if (adj[next].size() == 1) {
            leafs.insert({in[next], next});
        }
    }

    if (leafs.size() == 1) {
        cout << "YES\n";
    } else {
        cout << "NO\n";
    }
}