#include<bits/stdc++.h>

#define inf 0x3f3f3f3f

//const int maxn=;

using namespace std;

int t;

int n;

int main()

{

      scanf("%d",&t);

      while(t--){

        map<int, int> m;

        scanf("%d",&n);

        int ans = -inf;

        int cnt = ;

        int imax = ;

        int x;

        for(int i = ; i <= n; ++i){

                scanf("%d",&x);

                if(!m[x]){

                    ++cnt;

                } else {

                        ans = max(ans, cnt);

                        imax = max(imax, m[x] + );

                        cnt = i - imax + ;

                }

                m[x] = i;

        }

        ans = max(ans, cnt);

        printf("%d\n",ans);

      }

    return ;

}