A_MEX_Partition.cpp

#include <bits/stdc++.h>
using namespace std;

#define pb push_back 
#define all(v) v.begin(), v.end()
#define forn(i, k, n) for(int i = k; i < n; i++)
#define pyes cout<<"YES"<<endl;return
#define pno cout<<"NO"<<endl;return

typedef long long ll;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vll;

const int INF = 1e9;
const ll mod = 1000000007;

//The only verdict is vengeance; a vendetta, held as a votive, not in vain, for the value and veracity of such shall one day vindicate the vigilant and the virtuous.


void solve(){
    
    ll n; 
    cin >> n;
    vector<int> freq(102, 0);
    for (int i = 0; i < n; ++i) {
        ll a; 
        cin >> a;
        if (a >= 0 && a <= 101) freq[a]++;
    }
    int mex = 0;
    while (mex <= 101 && freq[mex] > 0) ++mex;
    cout << mex << '\n';
    
}



int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    
    int t=1;
    cin>>t;


    
        while(t--) 
            solve();

        return 0;
}