#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("YES");}else{puts("NO");}
#define MAX_N 200005
vector<int> G[MAX_N];
int main() {
    int n;
    cin >> n;
    rep(i,n-1){
        int a, b;
        cin >> a >> b;
        a--; b--;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    int r = -1;
    rep(i,n){
        if(G[i].size() >= 3){
            if(r != -1){
                cout << "No" << endl;
                return 0;
            }
            r = i;
        }
    }
    if(r == -1){
        cout << "Yes" << endl;
        return 0;
    }
    int f[n] = {};
    rep(i,n) f[i] = -1;
    f[r] = 0;
    int h = -1;
    queue<int> que;
    que.push(r);
    while(que.size()){
        int x = que.front();
        que.pop();
        rep(i,G[x].size()){
            int y = G[x][i];
            if(f[y] != -1) continue;
            f[y] = f[x] + 1;
            que.push(y);
        } 
        if(G[x].size() == 1){
            if(h == -1) h = f[x];
            if(f[x] != h){
                cout << "No" << endl;
                return 0;
            }
        }
    }

    cout << "Yes" << endl;
    return 0;
}