#line 1 "/home/siro53/kyo-pro/compro_library/template/template.cpp"
#include <bits/stdc++.h>
using namespace std;
template <class T> inline bool chmax(T &a, T b) {
    if(a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T> inline bool chmin(T &a, T b) {
    if(a > b) {
        a = b;
        return 1;
    }
    return 0;
}
#define DEBUG
#ifdef DEBUG
template <class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
    os << '(' << p.first << ',' << p.second << ')';
    return os;
}
template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
    os << '{';
    for(int i = 0; i < (int)v.size(); i++) {
        if(i) { os << ','; }
        os << v[i];
    }
    os << '}';
    return os;
}
void debugg() { cerr << endl; }
template <class T, class... Args>
void debugg(const T &x, const Args &... args) {
    cerr << " " << x;
    debugg(args...);
}
#define debug(...)                                                             \
    cerr << __LINE__ << " [" << #__VA_ARGS__ << "]: ", debugg(__VA_ARGS__)
#define dump(x) cerr << __LINE__ << " " << #x << " = " << (x) << endl
#else
#define debug(...) (void(0))
#define dump(x) (void(0))
#endif

struct Setup {
    Setup() {
        cin.tie(0);
        ios::sync_with_stdio(false);
        cout << fixed << setprecision(15);
    }
} __Setup;

using ll = long long;
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define FOR(i, a, b) for(int i = (a); i < int(b); i++)
#define REP(i, n) FOR(i, 0, n)
const int INF = 1 << 30;
const ll LLINF = 1LL << 60;
constexpr int MOD = 1000000007;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};

//-------------------------------------
#line 1 "/home/siro53/kyo-pro/compro_library/graph/tree_diameter.hpp"
vector<int> get_diameter_path(const vector<vector<int>> &G) {
    int n = (int)G.size();
    vector<int> depth(n), par(n);

    auto dfs = [&](auto &&dfs, int v, int p, int d) -> void {
        depth[v] = d;
        par[v] = p;
        for(const int &u : G[v]) {
            if(u != p) {
                dfs(dfs, u, v, d + 1);
            }
        }
    };

    dfs(dfs, 0, -1, 0);
    int from = max_element(ALL(depth)) - depth.begin();
    dfs(dfs, from, -1, 0);
    int to = max_element(ALL(depth)) - depth.begin();

    vector<int> res;
    int now = to;
    while(now != from) {
        res.emplace_back(now);
        now = par[now];
    }
    res.emplace_back(now);

    return res;
}
#line 3 "c.cpp"

int N;
vector<vector<int>> G;
vector<int> leafs, depth;

void dfs(int u, int p, int d) {
    bool is_leaf = true;
    depth[u] = d;
    for(int v : G[u]) {
        if(v == p) continue;
        is_leaf = false;
        dfs(v, u, d+1);
    }
    if(is_leaf) leafs.push_back(u);
}

int main() {
    cin >> N; G.resize(N);
    REP(i, N-1) {
        int a, b; cin >> a >> b; a--; b--;
        G[a].push_back(b); G[b].push_back(a);
    }

    auto dia = get_diameter_path(G);
    int len = dia.size();
    int center = dia[len / 2];

    depth.resize(N);
    dfs(center, -1, 0);

    set<int> se;
    for(int leaf : leafs) se.emplace(depth[leaf]);

    if(se.size() == 1) {
        cout << "Yes\n";
    } else{
        cout << "No\n";
    }
}