#include <bits/stdc++.h>
using namespace std;

int main() {
    int N;
    cin >> N;
    vector<vector<int>>ki(N);
    for(int i = 0; i < N-1; i++) {
        int a,b;
        cin >> a >> b;
        a--;
        b--;
        ki[a].push_back(b);
        ki[b].push_back(a);
    }
    vector<int>tmp;
    for(int i = 0; i < N; i++) {
        if(ki[i].size() == 1) {
            tmp.push_back(i);
        }
    }
    if(tmp.size() == 2) {
        cout << "Yes" << endl;
        return 0;
    }
    vector<int>dist(N,-1);
    dist[tmp[0]] = 0;
    queue<int>que;
    que.push(tmp[0]);
    while(!que.empty()) {
        int x = que.front();
        que.pop();
        for(int i = 0; i < ki[x].size(); i++) {
            if(dist[ki[x][i]] == -1) {
                dist[ki[x][i]] = dist[x]+1;
                que.push(ki[x][i]);
            }
        }
    }
    if(dist[tmp[1]]%2 == 1) {
        cout << "No" << endl;
    }
    else {
        vector<int>tmp2;
        tmp2.push_back(tmp[1]);
        que.push(tmp[1]);
        while(!que.empty()) {
            int x = que.front();
            que.pop();
            for(int i = 0; i < ki[x].size(); i++) {
                if(dist[ki[x][i]] == dist[x]-1) {
                    tmp2.push_back(ki[x][i]);
                    que.push(ki[x][i]);
                }
            }
        }
        int p = tmp2[tmp2.size()/2];
        vector<int>dist2(N,-1);
        dist2[p] = 0;
        set<int>st;
        for(int i = 0; i < ki[p].size(); i++) {
            que.push(ki[p][i]);
            dist[ki[p][i]] = 1;
            int res = 0;
            while(!que.empty()) {
                int x = que.front();
                que.pop();
                for(int i = 0; i < ki[x].size(); i++) {
                    if(dist2[ki[x][i]] == -1) {
                        dist2[ki[x][i]] = dist2[x]+1;
                        que.push(ki[x][i]);
                        if(ki[ki[x][i]].size() == 1) {
                            res++;
                            st.insert(dist2[ki[x][i]]);
                        }
                    }
                }
            }
            if(res >= 2) {
                cout << "No" << endl;
                return 0;
            }
        }
        if(st.size() == 1) {
            cout << "Yes" << endl;
        }
        else {
            cout << "No" << endl;
        }
        
    }
}