#include <bits/stdc++.h>

using namespace std;

using graph = vector<vector<int>>;

void dfs(const graph &to, vector<int> &d, int v, int p)
{
    for (auto &&c : to.at(v))
    {
        if (c == p)
        {
            continue;
        }
        d.at(c) = d.at(v) + 1;
        dfs(to, d, c, v);
    }
}

int main(int argc, char const *argv[])
{
    int n;
    cin >> n;
    graph to(n);
    for (int i = 0; i < n - 1; i++)
    {
        int a, b;
        cin >> a >> b;
        a--;
        b--;
        to.at(a).push_back(b);
        to.at(b).push_back(a);
    }
    vector<int> d(n);
    dfs(to, d, 0, -1);
    int v = max_element(d.begin(), d.end()) - d.begin();
    d.at(v) = 0;
    dfs(to, d, v, -1);
    int dmax = *max_element(d.begin(), d.end());
    if (dmax == n - 1)
    {
        cout << "Yes" << endl;
        return 0;
    }
    if (dmax % 2)
    {
        cout << "No" << endl;
        return 0;
    }
    int center = 0;
    for (int i = 0; i < n; i++)
    {
        if (d.at(i) == dmax / 2)
        {
            center = i;
            break;
        }
    }
    d.at(center) = 0;
    dfs(to, d, center, -1);
    int diff = 0;
    for (int i = 0; i < n; i++)
    {
        if (to.at(i).size() == 1 and d.at(i) != dmax / 2)
        {
            cout << "No" << endl;
            return 0;
        }
        if (to.at(i).size() == 1)
        {
            diff++;
        }
        if (d.at(i) == 1)
        {
            diff--;
        }
    }
    if (diff == 0)
    {
        cout << "Yes" << endl;
    }
    else
    {
        cout << "No" << endl;
    }
    return 0;
}