lis (diff by 1)

// Those who cannot remember the past are
// condemned to repeat it (use DP -_-)
// - George Santayana

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define ll long long
#define ull unsigned long long
#define MOD 1000000007
#define PI 3.14159265
#define ceil(a, b) (((a) / (b)) + ((a) % (b) ? 1 : 0))
#define imin INT_MIN
#define imax INT_MAX
#define llmax LLONG_MAX
#define llmin LLONG_MIN
#define inf 2000000000
#define nl '\n'
#define ppcnt __builtin_popcount
#define ppcntll __builtin_popcountll
#define clz __builtin_clz
#define clzll __builtin_clzll
#define ctz __builtin_ctz
#define ctzll __builtin_ctzll
#define modulo(a, b, mod) ((((a) % (mod)) + ((b) % (mod))) % (mod))
#define cnte(v, x) count(all(v), (x))
#define mine(v) min_element(all(v))
#define maxe(v) max_element(all(v))
#define updmin(a, b) a = min(a, b)
#define updmax(a, b) a = max(a, b)
#define finmod(x, m) x = ((x) % (m) + (m)) % m
#define debug(x) cout << "x: " << (x) << nl;
#define debug2(x, y) cout << "x: " << (x) << " y: " << y << nl;
#define ordered_set tree<pair<int, int>, null_type, less<>, rb_tree_tag, tree_order_statistics_node_update>
#define ordered_map tree<int, int, less<>, rb_tree_tag, tree_order_statistics_node_update>

//vector<int> dx = {0, 0, 1, -1, 1, 1, -1, -1}, dy = {1, -1, 0, 0, 1, -1, 1, -1};
//vector<int> dx = {0, 0, 1, -1}, dy = {1, -1, 0, 0};

template<typename T = int> istream& operator>>(istream& in, vector<pair<int, int>>& v){
    for (auto& [x, y] : v) in >> x >> y;
    return in;
}

template<typename T = int> istream& operator>>(istream& in, vector<T>& v){
    for (T& i : v) in >> i;
    return in;
}

template<typename T = int> ostream& operator<<(ostream& out, const vector<T>& v){
    for (const T& x : v)
        out << x << ' ';
    return out;
}

template<typename T = pair<ll, ll>> ostream& operator << (ostream& out, const vector<pair<ll, ll>>& v){
    for(auto& [x, y] : v){
        out << x << ' ' << y << nl;
    }
    return out;
}

void Start_Crushing() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
}
vector<int> v, memo;
vector<vector<int>> mp;

int bs(int target, vector<int>& range){
    int left = -1, right = (int)range.size() - 1;

    while(left < right - 1){
        int mid = left - (left - right) / 2;

        if(range[mid] > target)
            right = mid;
        else
            left = mid;
    }

    return range[right] > target ? right : -1;
}

int lis(int idx = 0){
    if(mp[v[idx] + 1].empty())
        return 1;

    int& ret = memo[idx];
    if(~ret)
        return ret;

    ret = 1;
    int st = bs(idx, mp[v[idx] + 1]);

    if(~st){
        while(st != mp[v[idx] + 1].size()){
            updmax(ret, lis(mp[v[idx] + 1][st++]) + 1);
        }
    }

    return ret;
}

void solve(){
    int n; cin >> n;
    v.resize(n);
    mp.assign(20005, vector<int>());
    memo.assign(n + 5, -1);

    for(int i = 0; i < n; i++){
        cin >> v[i];
        mp[v[i]].emplace_back(i);
    }

    int res = imin;
    for(int i = 0; i < n; i++){
        updmax(res, lis(i));
    }
    cout << res;
}

int main(){
    Start_Crushing();

    int t = 1;
    /*Multiple test cases?*/ cin >> t;
    while (t--) {
        solve();
        if(!t)
            break;
        cout << nl;
    }

//    for(int tc = 1; tc <= t; tc++){
//        cout << "Case #" << tc << ": ";
//        solve();
//        if(tc != t)
//            cout << nl;
//    }

    return 0;
}