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

#define tsolve int t; cin >> t; while (t--) solve
#define all(x) ::begin(x), ::end(x)
#define sz(x) (ll)::size(x)

using ll = long long;
using ld = long double;

int n;
vector<vector<int>> g;

vector<int> s;

void dfs_sz(int v, int from = -1){
    s[v] = 1;
    for(int u : g[v]){
        if(u != from){
            dfs_sz(u, v);
            s[v] += s[u];
        }
    }
}

vector<int> cents;

void dfs_cent(int v, int from){
    for(int u : g[v]){
        if(u != from){
            if(2*s[u] == n){
                cents.push_back(v);
                cents.push_back(u);
                return;
            }
            if(2*s[u] > n){
                dfs_cent(u, v);
                return;
            }
        }
    }
    cents.push_back(v);
}

bool ok = true;

void dfs(int u, int par){
    vector<int> vals;
    for(int v : g[u]){
        if(v != par) vals.push_back(s[v]);
    }
    sort(all(vals));
    int x = 1;
    for(int y : vals){
        if(y > x) ok = false;
        x += y;
    }
    for(int v : g[u]) if(v != par) dfs(v, u);
}

void solve() {
    cin >> n;
    g.resize(n);
    for(int i = 0; i < n-1; i++){
        int u, v;
        cin >> u >> v;
        u--, v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    s.resize(n);
    dfs_sz(0);
    dfs_cent(0, -1);
    bool ans = false;
    for(int u : cents){
        dfs_sz(u);
        ok = true;
        dfs(u, -1);
        if(ok) ans = true;
    }
    if(ans) cout << "YES\n";
    else cout << "NO\n";
}

int main() {
    cin.tie(0)->sync_with_stdio(false);
    cout << setprecision(16);
    solve();
}