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

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

void solve() {
    ll n;
    cin >> n;
    vector<set<ll>> adj(n);
    rep(i,0,n-1) {
        int u, v;
        cin >> u >> v;
        adj[--u].insert(--v);
        adj[v].insert(u);
    }
    /*
    function<ll(ll,ll)> dfs = [&] (ll u, ll p) {
        vi sizes;
        for (auto x : adj[u]) {
            if (x == p) continue;
            sizes.push_back(dfs(x, u));
        }
        sort(all(sizes));
        ll acc = 1;
        for (auto x : sizes) {
            if (x > acc) {cout << "NO\n", exit(0); }
            acc += x;
        }
        return acc;
    };*/
    priority_queue<pii,vector<pii>,greater<>> pq;
    rep(i,0,n) {
        if (ssize(adj[i]) > 1) continue;
        pq.emplace(1, i);
    }
    vi st(n, 1);
    while (!empty(pq)) {
        auto [d, u] = pq.top();
        pq.pop();
        if (empty(adj[u])) continue;
        assert(ssize(adj[u]) == 1);
        auto v = *begin(adj[u]);
        if (st[v] < st[u]) cout << "NO\n", exit(0);
        st[v] += st[u];
        adj[v].erase(u);
        if (ssize(adj[v]) == 1) pq.emplace(st[v], v);
    }
    cout << "YES\n";
}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);

    //ll t; cin >> t; while(t--)
        solve();
}