#include<bits/stdc++.h>
#define int long long
#define b bool
using namespace std;
const int N = 11;
const int inf = 0x3f3f3f3f;
int a[N];
bool hqt[N];
int sum;
int n;
int ans;
bool dfs(int s , int ans){
	if(s > sum){
		return false;
	}
	
	if(sum == s){
		ans ++;
		if(ans == 3){	
			return true;
		}
		s = 0;
	}
	for(int i = 1 ; i <= n ; i ++){
		if(hqt[i]){
			continue;
		}
		hqt[i] = true;
		if(dfs(s + a[i] , ans)){
			return true;
		}
		hqt[i] = false;
	}
	return false;
}
signed 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;
	}else{
		sum /= 3;
	}
	if(dfs(0 , 0)){
		cout << "yes";
	}else{
		cout << "no";
	}
	return 0;
}