#include<iostream>
#include<algorithm>
using namespace std;
int number[10];
int k;
int Type(int a){
    if (a % 2 == 1&&a!=5)
        return -1;
    else if (a==5)
        return 0;
    else if (a == 4 || a == 6)
        return 1;
    else
        return 2;
}
int main(){
    int T, i,j;
    bool flag;
    bool W[10];
    cin >> T;
    while (T--){
        memset(W, 0, sizeof(W));
        flag = 1;
        cin >> k;
        if (k)
        for (i = 0; i < k; i++){
            cin >> number[i];
            if (number[i]>9||number[i]==0)
                flag = 0;
            for (j = 0; j < i; j++){
                if (number[i] == number[j])
                    flag = 0;
            }
        }
        if (k<4||!flag)
            flag = 0;
        else{
            for (i = 0; i < k-1; i++){
                if (Type(number[i]) == Type(number[i + 1]) && !W[(number[i] + number[i + 1])/ 2]){
                    flag = 0;
                    break;
                }
                else
                    W[number[i]] = 1;
            }
        }
        if (flag)
            cout << "valid" << endl;
        else
            cout << "invalid" << endl;
    }
    return 0;
}