#include "stack"
#include "stdio.h"
#include "iostream"
#include "math.h"
#include "string.h"
#include "algorithm"
#include "queue"
#include <fstream>
#define LL long long
#define N 1111
#define inf 0x7ffffff
#define pi 3.1415926535897932384626433832795028841971
using namespace std;
int main()
{
    int i,j,k,n,flag,a[N];
    while(~scanf("%d",&n))
    {
        for(i=1;i<=n;i++)
            scanf("%d",&a[i]);
        flag=1;
        for(i=1;i<=n&&flag;i++)
        {
            for(j=1;j<=n&&flag;j++)
            {
                for(k=1;k<=n&&flag;k++)
                {
                    if(i!=j&&j!=k&&i!=k&&a[i]+a[j]==a[k])
                        flag=0;
                }
            }
        }
        if(flag)
            printf("NO\n");
        else
            printf("YES\n");
    }
    return 0;
}