#include <iostream>
#include <cstring>
#include <cstdio>
#define LL long long
#define Mod 1000000007
using namespace std;
using namespace std;

int a[22], H[22];

int mid(int a, int b)
{
    if(a > b)
        swap(a, b);
    if(a == 1 && b == 9)
        return 5;
    if(a == 3 && b == 7)
        return 5;
    if((a <= 3 && b == a + 6) || (a % 3 == 1 && b == a + 2))
        return (a+b)/2;
    return -1;

}

bool Judge(int n)
{
    if(n < 4)
        return false;
    memset(H, 0, sizeof(H));
    for(int i=0; i<n; i++)
    {
        if(a[i]<=0 ||a[i] > 9)
            return false;
        if(H[a[i]])
            return false;
        H[a[i]]++;
    }
    bool vis[22];
    memset(vis, false, sizeof(vis));
    for(int i=1; i<n; i++)
    {
        int t = mid(a[i], a[i-1]);
        if(t != -1 && !vis[t])
            return false;
        vis[a[i-1]] = true;
    }
    return true;

}


int main()
{
    int T,n;
    scanf("%d",&T);
    while(T-- && scanf("%d",&n))
    {
        for(int i=0; i<n; i++)
            scanf("%d",&a[i]);
        if(Judge(n))
            cout<<"valid"<<endl;
        else
            cout<<"invalid"<<endl;
    }
    return 0;
}