#include <bits/stdc++.h>
#define pii pair <int, int>

using namespace std;

set <int> g[200005];
int deg[200005], value[200005];
priority_queue <pii> pq;

void solve() {
    int n;
    cin >> n;
    for(int i = 1; i < n; i++) {
        int x, y;
        cin >> x >> y;
        g[x].insert(y);
        g[y].insert(x);
        deg[x]++, deg[y]++;
    }
    for(int i = 1; i <= n; i++) {
        value[i] = 1;
        if(deg[i] == 1)
            pq.push({-deg[i], i});
    }
    int op = 0;
    while(!pq.empty() && ++op <= n - 2) {
        pii p = pq.top();
        pq.pop();
        int node = p.second;
        int par = *g[node].begin();
        //cout << par << " " << node << " " << val << "\n";
        g[par].erase(node);
        g[node].clear();
        if(value[par] < value[node]) {
            cout << "NO\n";
            return;
        }
        value[par] += value[node];
        value[node] = 0;
        if(g[par].size() == 1)
            pq.push({-value[par], par});
    }
    cout << "YES\n";
}

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

#ifdef LOCAL
    freopen("test.in", "r", stdin);
    freopen("test.out", "w", stdout);
#else

#endif
    int T = 1;
    //cin >> T;
    while(T--) {
        solve();
    }
    return 0;
}