#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using ull=unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)
using mll=atcoder::static_modint<1000000007>;

int N;
vector<vector<int>> E;
vector<int> D;

int main(){
  scanf("%d",&N);
  E.resize(N);
  rep(i,N-1){
    int u,v; scanf("%d%d",&u,&v); u--; v--;
    E[u].push_back(v);
    E[v].push_back(u);
  }
  int splitCount=0;
  rep(i,N) if(E[i].size()>2) splitCount++;
  if(splitCount==0){ printf("Yes\n"); return 0; }
  if(splitCount>=2){ printf("No\n"); return 0; }

  queue<int> Q;
  rep(i,N) if(E[i].size()>2){ D[i]=0; Q.push(i); }
  D.assign(N,-1);
  while(Q.size()){
    int p=Q.front(); Q.pop();
    for(int e:E[p]) if(D[e]==-1){ D[e]=D[p]+1; Q.push(e); }
  }
  int x=-1;
  rep(i,N) if(E[i].size()==1){
    if(x==-1) x=D[i];
    else if(x!=D[i]){ printf("No\n"); return 0; }
  }
  
  printf("Yes\n");
  return 0;
}