#include <iostream>
#include <cstdio>
#include <cstring>
#include <queue>
#include <cstdlib>
#include <algorithm>
#include <stack>
#include <set>
#include <map>
#include <vector>
#include <string>
#define RR freopen("in.txt","r",stdin)
#define WW freopen("out.txt","w",stdout)
#define LL long long
#define INF 0x3f3f3f3f
#define Lson l,mid,rt<<1
#define Rspn mid+1,r,rt<<1|1

using namespace std;

int main()
{
    int a[110],n;
    while(~scanf("%d",&n))
    {
        int f=0;
        for(int i=1;i<=n;i++)
            scanf("%d",a+i);
        for(int i=1;i<=n;i++){
            for(int j=1;j<=n;j++){
                for(int k=1;k<=n;k++)
                    if(i!=j && j!=k && i!=k)
                        if(a[i]-a[j]==a[k]) {f=1;break;}
                if(f) break;
            }
            if(f) break;
        }
        if(f) printf("YES\n");
        else printf("NO\n");
    }
    return 0;
}