#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
using ll = long long;

int d0 = -1, d1 = 1 << 30, r = 1;

struct Graph {
    struct Vertex { int n, k; };
    struct Edge { int i, n; };
    Graph(int n, int m) : v(n, { -1 }), e(m), n(n), m(0) {}
    void add_edge(int a, int b) {
        e[m] = { b, v[a].n };
        v[a].n = m;
        m++;
    }
    void dfs(int i, int p, int d) {
        if (d1 > n && v[i].k > 2) d1 = d;
        for (int j = v[i].n; j >= 0; j = e[j].n) {
            Edge &o = e[j];
            if (o.i == p) continue;
            dfs(o.i, i, d + 1);
        }
        if (d > 0 && v[i].k == 1) {
            if (d0 < 0) d0 = d; else if (d != d0) r = 0;
        }
        if (d > d1 && v[i].k > 2) r = 0;
    }
    void solve() {
        for (int i = 0; i < n; i++) {
            int k = 0;
            for (int j = v[i].n; j >= 0; j = e[j].n) {
                k++;
            }
            v[i].k = k;
        }
        for (int i = 0; i < n; i++) {
            if (v[i].k == 1) {
                dfs(i, -1, 0);
                if (d1 < n && d0 != d1 * 2) r = 0;
                cout << (r ? "Yes" : "No") << endl;
                exit(0);
            }
        }
    }
    vector<Vertex> v;
    vector<Edge> e;
    int n, m;
};

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

    int n;
    cin >> n;

    Graph g(n, (n - 1) * 2);
    for (int i = 0; i < n - 1; i++) {
        int a, b;
        cin >> a >> b;
        a--; b--;

        g.add_edge(a, b);
        g.add_edge(b, a);
    }
    g.solve();

    return 0;
}