#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
 ll MOD=1000000007;
 ll MOD9=998244353;
 int inf=1e9+10;
 ll INF=1e18;
 ll dy[8]={1,0,-1,0,1,1,-1,-1};
 ll dx[8]={0,1,0,-1,1,-1,1,-1};
template <typename T> inline bool chmax(T &a, T b) {
  return ((a < b) ? (a = b, true) : (false));
}
template <typename T> inline bool chmin(T &a, T b) {
  return ((a > b) ? (a = b, true) : (false));
}
vvl g(100010);
bool ans=true;
ll dim=0;
ll dfs(ll v,ll par=-1){//もっとも遠い頂点の距離
  ll ret=0;
  vl vs;
  for(auto p:g[v]){
    if(p==par)continue;
    vs.push_back(dfs(p,v));
  }
  sort(all(vs));
  if(vs.size())if(*vs.begin()!=*vs.rbegin())ans=false;
  if(vs.size())chmax(ret,vs[0]);
  if(vs.size()>1){
    if(dim==0)dim=ret*2;
    else {
      if(dim!=ret*2)ans=false;
    }
  }
  ret++;
  return ret;
}
int main(){
  ll n;cin >> n;
  rep(i,n-1){
    ll a,b;cin >>a  >> b;a--;b--;
    g[a].pb(b);g[b].pb(a);
  }
  ll s=-1;
  rep(i,n)if(g[i].size()==1)s=i;
  ll p=dfs(s);p--;
  if((ans&&(p==dim))||dim==0)cout << "Yes" <<endl;
  else cout << "No" <<endl;

}