#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define chmin(x,y) x = min((x),(y));
#define chmax(x,y) x = max((x),(y));
using namespace std;
using ll = long long ;
using P = pair<int,int> ;
using pll = pair<long long,long long>;
const int INF = 1e9;
const long long LINF = 1e17;
const int MOD = 1000000007;
//const int MOD = 998244353;
const double PI = 3.14159265358979323846;



int main(){
    int n;
    cin >> n;
    vector<vector<int>> G(n);
    rep(i,n-1){
        int a,b;
        cin >> a >> b;
        --a;--b;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    bool ok = true;
    int one = 0;
    rep(i,n){
        if((int)G[i].size() == 1){
            ++one;
        }
        else if((int)G[i].size() != 2){
            ok = false;
        }
    }
    if(one == 2 && ok){
        cout << "Yes" << endl;
        return 0;
    }
    vector<int> dis(n,0);
    auto dfs = [&](auto&& dfs,int i,int p,int c) -> void{
        dis[i] = c;
        for(int j:G[i]){
            if(j == p) continue;
            dfs(dfs,j,i,c + 1);
        }
        return;
    };
    dfs(dfs,0,-1,0);
    int ma = 0,ind = -1;
    rep(i,n){
        if(ma < dis[i]){
            ma = dis[i];
            ind = i;
        }
    }
    dfs(dfs,ind,-1,0);
    ma = 0;
    rep(i,n) chmax(ma,dis[i]);

    if(ma % 2 == 1){
        cout << "No" << endl;
        return 0;
    }

    rep(i,n){
        if((int)G[i].size() == 1){
            if(dis[i] != ma && dis[i] != 0){
                cout << "No" << endl;
                return 0;
            }
        }
    }

    
    ind = -1;
    rep(i,n){
        if(dis[i] == (ma / 2)){
            ind = i;
            break;
        }
    }
    dfs(dfs,ind,-1,0);
    rep(i,n){
        if((int)G[i].size() == 1){
            if(dis[i] != ma / 2){
                cout << "No" << endl;
                return 0;
            }
        }
    }

    ok = true;
    one = 0;
    rep(i,n){
        if((int)G[i].size() != 2 && (int)G[i].size() != 1 && i != ind){
            cout << "No" << endl;
            return 0;
        }
    }
    cout << "Yes" << endl;
    
    return 0;
}