#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 2e5 + 10;
const int mod = 1e12 + 7;
int n, t, x, y;
vector<int> Edge[N];
int Hash(int x, int f, int t) { // t = 1 是否对称; t = 0 Hash
    if (t == 1) {
        map <int, int> s;
        for (int i : Edge[x])
            if (i != f) {
                int h = Hash(i, x, 0);
                if (s[h])
                    s.erase(h);
                else
                    s[h] = i;
            }
        if (s.size() >= 2) return 0;
        if (s.size() == 0) return 1;
        return Hash(s.begin()->second, x, 1);
    } else {
        int ans = N;
        vector <int> q;
        for (int i : Edge[x])
            if (i != f) 
                q.push_back(Hash(i, x, 0));
        sort(q.begin(), q.end());
        for (int i : q) ans = (ans * 2333 + i) % mod;
        return (ans * 2333 * N + 1) % mod;
    }
}
signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    cin >> t;
    while (t--) {
        cin >> n;
        for (int i = 1; i <= n; i++) Edge[i].clear();
        for (int i = 1; i < n; i++) {
            cin >> x >> y;
            Edge[x].push_back(y);
            Edge[y].push_back(x);
        }
        cout << (Hash(1, 0, 1) ? "YES\n" : "NO\n");
    }
    return 0;
}