description: Petya has got an interesting flower. Petya is a busy person, so he sometimes forgets to water it. You are given n days from Petya's live and you have to determine what happened with his flower in the end.
  
  The flower grows as follows: 
  
    * If the flower isn't watered for two days in a row, it dies. 
    * If the flower is watered in the i-th day, it grows by 1 centimeter. 
    * If the flower is watered in the i-th and in the (i-1)-th day (i > 1), then it grows by 5 centimeters instead of 1. 
    * If the flower is not watered in the i-th day, it does not grow. 
  
  
  
  At the beginning of the 1-st day the flower is 1 centimeter tall. What is its height after n days?
  
  Input
  
  Each test contains multiple test cases. The first line contains the number of test cases t (1 ≤ t ≤ 100). Description of the test cases follows.
  
  The first line of each test case contains the only integer n (1 ≤ n ≤ 100).
  
  The second line of each test case contains n integers a_1, a_2, ..., a_n (a_i = 0 or a_i = 1). If a_i = 1, the flower is watered in the i-th day, otherwise it is not watered.
  
  Output
  
  For each test case print a single integer k — the flower's height after n days, or -1, if the flower dies.
  
  Example
  
  Input
  
  
  4
  3
  1 0 1
  3
  0 1 1
  4
  1 0 0 1
  1
  0
  
  
  Output
  
  
  3
  7
  -1
  1
solution: // Piyush Nagpal
  import java.util.*;
  import java.io.*;
   public class C{
       
      static int MOD=1000000007;
      static PrintWriter pw;
      static FastReader sc;
      
      static class FastReader {
          BufferedReader br;
          StringTokenizer st;
   
          public FastReader()
          {
              br = new BufferedReader(
                  new InputStreamReader(System.in));
          }
   
          String next()
          {
              while (st == null || !st.hasMoreElements()) {
                  try {
                      st = new StringTokenizer(br.readLine());
                  }
                  catch (IOException e) {
                      e.printStackTrace();
                  }
              }
              return st.nextToken();
          }
   
          int nextInt() { return Integer.parseInt(next()); }
   
          long nextLong() { return Long.parseLong(next()); }
   
          double nextDouble(){return Double.parseDouble(next());}
          
          public char nextChar() throws IOException {return next().charAt(0);}
   
          String nextLine(){
              String str = "";
              try {
                  str = br.readLine();
              }
              catch (IOException e) {
                  e.printStackTrace();
              }
              return str;
          }
          public int[] intArr(int a,int b,int n) throws IOException {int[]in=new int[n];for(int i=a;i<b;i++)in[i]=nextInt();return in;}
          public long[] longArr(int a,int b,int n) throws IOException {long[]in=new long[n];for(int i=a;i<b;i++)in[i]=nextLong();return in;}
          public ArrayList<Integer> intlist(int n)throws IOException {ArrayList<Integer> list= new ArrayList<>();for(int i=0;i<n;i++)list.add(nextInt());return list;}
          public ArrayList<Long> longlist(int n)throws IOException {ArrayList<Long> list= new ArrayList<>();for(int i=0;i<n;i++)list.add(nextLong());return list;}
      }   
   
   
       public static long gcd(long a,long b){if( b>a ){return gcd(b,a);}if( b==0 ){return a;} return gcd(b,a%b);}
       public static long expo( long a,long b,long M ){long result=1;while(b>0){if( b%2==1 ){result=(result*a)%M;}a=(a*a)%M;b=b/2;}return result%M;}
      public static ArrayList<Long> Sieve(int n){boolean [] arr= new boolean[n+1];Arrays.fill(arr, true);ArrayList<Long> list= new ArrayList<>();for(int i=2;i<=n;i++){if( arr[i]==true ){list.add((long)i);}for(int j=2*i;j<=n;j+=i){arr[j]=false;}}return list;}
   
      public static void parr(int [] arr){for(int i=0;i<arr.length;i++){pw.print(arr[i]+" ");}}
      public static void parr(long [] arr){for(int i=0;i<arr.length;i++){pw.print(arr[i]+" ");}}
      public static void plist(ArrayList<Integer> list){for(int i=0;i<list.size();i++){pw.print(list.get(i)+" ");}}
      public static void pllist(ArrayList<Long> list){for(int i=0;i<list.size();i++){pw.print(list.get(i)+" ");}}
      
      // int [] arr=sc.intArr(a,b,n);  <b
      static void solve() throws Exception{
          int n=sc.nextInt();
          int [] arr= sc.intArr(0,n,n);
  
          int ans =1;
  
          for(int i=0;i<n;i++){
              if(i==0){
                  if(arr[0]==1){
                      ans++;
                  }
              }else{
                  if(arr[i]==1 && arr[i-1]==1){
                      ans+=5;
                  }else if(arr[i]==1){
                      ans++;
                  }else if(arr[i]==0 && arr[i-1]==0){
                      pw.println("-1");
                      return;
                  }
              }
          }
          pw.println(ans);
  }
  
     public static void main(String[] args) throws Exception{
          try {
              System.setIn(new FileInputStream("input.txt"));
              System.setOut(new PrintStream(new FileOutputStream("output.txt")));
          } catch (Exception e) {
              System.err.println("Error");
          }
          sc= new FastReader();
          pw = new PrintWriter(System.out);
  
          int tc=1;
          tc=sc.nextInt();
          for(int i=1;i<=tc;i++) {
             // pw.printf("Case #%d: ", i);
              solve();
          }
         
          pw.flush();
   
      
   
      }
   
  }