#include<stdio.h>
#include<stdlib.h>
#include<iostream>
#include<string.h>
#include<cstring>
#include<string>
#include<algorithm>
using namespace std;
int Arr[105];
int sum = 0, i = 0, j = 0, k = 0,n=0;
void solve()
{

    for (i = 0; i<n; i++){
        for (j = i + 1; j<n; j++){
            sum = Arr[i] + Arr[j];
            for (k = j + 1; k<n; k++){
                if (Arr[k] == sum){
                    printf("YES\n");
                    return;
                }
            }
        }
    }
    printf("NO\n");
}
int main()
{

    while (cin >> n){
        for (i = 0; i<n; i++){
            scanf("%d", &Arr[i]);
        }
        sort(Arr, Arr + n);
        solve();
    }
    return 0;
}