#include<bits/stdc++.h>
using namespace std;
const int N=100010;
int a[N],n;
bool work(int u)
{
    for(int i=u-1;i>=1;i--)
    {
        for(int j=u+1;j<=n;j++)
        {
            if(a[u]-a[i]==a[j]-a[u])
            {
                return true;
            }
        }
    }
    return false;
}
int main()
{
    freopen("sequence.in","r",stdin);
    freopen("sequence.out","w",stdout);
    int t;
    cin>>t;
    for(int i=1;i<=t;i++)   
    {
        bool found=false;
        cin>>n;
        memset(a,0,sizeof(a));
        for(int j=1;j<=n;j++) cin>>a[j];
        for(int j=1;j<=n;j++)
        {
            if(work(j))
            {
                cout<<"Y"<<endl;
                found=true;
                break;
            }
        }
        if(!found)
        {
            cout<<"N"<<endl;
        }
    }
    return 0;
}