using namespace std;
const int N=1e4+10;
int a[N],sum=0,n;
bool vis[N];
bool dfs(int cnt,int ans){
if(cnt>sum){
return false;
}
if(cnt==sum){
ans++;
if(ans==3){
return true;
}
cnt=0;
}
for(int i=1;i<=n;i++){
if(vis[i]){
continue;
}
vis[i]=true;
if(dfs(cnt+a[i],ans)){
return true;
}

vis[i]=false;
}
return false;


}
int main (){
freopen("triangle.in", "r", stdin);
freopen("triangle.out", "w", stdout);
cin>>n;
for(int i=1;i<=n;i++){
cin>>a[i];
sum+=a[i];
}
if(sum%3!=0){
cout<<"no";
return 0;
}
sum/=3;
if(dfs(0,0)){
cout<<"yes";
}else{
cout<<"no";
}
return 0;
}