//2022tysc0819
#include<bits/stdc++.h>
//#include<bits/extc++.h>
using namespace std;
//using namespace __gnu_pbds;
//#define int long long
//#define double long double
//#define map unordered_map
//#pragma GCC optimize(2,3,"Ofast","inline")
const int N=1e6+10,M=1e9+1,P=1e5,MOD=998244353;
const double PI=3.1415926,EPS=0.00001;
int n,a[N],ans,T;
queue<int>q;
bitset<M>mp;
signed solve(){
    cin>>n;
    while(q.size())q.pop();
    for(int i=1;i<=n;i++){
        cin>>a[i];
        while(mp[a[i]]!=0&&q.size()){mp[q.front()]=0;q.pop();}
        q.push(a[i]);mp[a[i]]=1;
        ans=max(ans,(int)q.size());
    }
    cout<<ans<<'\n';
    return 0;
}
signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    cin>>T;while(T--)solve();
    return 0;
}
//note: