#include <bits/stdc++.h>

using namespace std;

using ll = long long;

int main(){

    int t;
    cin >> t;

    while(t--){

        int n;
        cin >> n;

        vector<pair<int, int>> v(n);

        for(int i = 0; i < n; i++){
            int prev;
            cin >> prev;
            prev--;
            if(prev != -1) v[prev].second = i-1;
            v[i] = {i, i};
        }

        vector<int> pre(n+3, 0);
        for(int i = 0; i < n; i++){
            auto [f, s] = v[i];
            pre[f]++;
            pre[s+1]--;
        }

        int ans = 0;
        for(int i = 0; i <= n; i++){
            if(i)
            pre[i] += pre[i-1];
            ans = max(ans, pre[i]);
        }

        cout << ans << endl;

    }

}