//#include <tourist>
#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
typedef long long ll;
typedef long double ld;
typedef unsigned int uint;
typedef unsigned long long ull;

typedef pair<ll, ll> p;
const int INF = 1e9;
const double eps = 1e-7;
const ll LINF = ll(1e18);
const int MOD = 1000000007;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};
const int Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1}, Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
const long double pi = 4 * atan(1);
#define yes cout << "Yes" << endl
#define YES cout << "YES" << endl
#define no cout << "No" << endl
#define NO cout << "NO" << endl
#define rep(i, n) for (int i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()
#define debug(v)          \
    cout << #v << ":";    \
    for (auto x : v)      \
    {                     \
        cout << x << ' '; \
    }                     \
    cout << endl;
template <class T>
bool chmax(T &a, const T &b)
{
    if (a < b)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
bool chmin(T &a, const T &b)
{
    if (b < a)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &v)
{
    for (T &x : v)
        is >> x;
    return is;
}
//cout<<fixed<<setprecision(15);有効数字15桁
//-std=c++14
//g++ yarudake.cpp -std=c++17 -I .
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

int dfs(int cur, int prev, vector<vector<int>> &v)
{
    int res = 0;
    rep(i, v[cur].size())
    {
        if (v[cur][i] == prev)
            continue;
        if (res == 0)
        {
            res = dfs(v[cur][i], cur, v) + 1;
        }
        else if (res > 0)
        {
            int temp = dfs(v[cur][i], cur, v) + 1;
            if (res != temp)
            {
                return -1;
            }
        }
    }
    return res;
}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    vector<vector<int>> v(n);
    rep(i, n - 1)
    {
        int a, b;
        cin >> a >> b;
        a--;
        b--;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    int count = 0;
    int c;
    rep(i, n)
    {
        if (v[i].size() >= 3)
        {
            count++;
            c = i;
        }
    }
    if (count >= 2)
    {
        no;
        return 0;
    }
    if (count == 0)
    {
        yes;
        return 0;
    }
    int ans = dfs(c, -1, v);
    if (ans == -1)
        return no, 0;
    else
        yes, 0;
}