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: /*
  
  Sample Input 1
  
  4
  3
  1 0 1
  3
  0 1 1
  4
  1 0 0 1
  1
  0
  
  Sample Output 1
  
  3
  7
  -1
  1
  
  */
  import java.io.*;
  import java.util.*;
    
  public class R1591A
  {
      static int MAX(int x, int y){return ((x > y) ? x : y );}
      static int MIN(int x, int y){return ((x < y) ? x : y );}
      static int sum(int[] A){int sum = 0;for(int i=0; i<A.length; i++)sum+=A[i];return (sum);}
      static int gcd(int a, int b){if (b == 0)return a;return gcd(b, a % b);}
      static boolean isPowerOfTwo(int n){if(n==0)return false;return (int)(Math.ceil((Math.log(n) / Math.log(2)))) ==(int)(Math.floor(((Math.log(n) / Math.log(2)))));}
      static void swap(int[] a, int idx1, int idx2){if (a[idx1] == a[idx2])return;a[idx1] ^= a[idx2];a[idx2] ^= a[idx1];a[idx1] ^= a[idx2];}
      static int countDigits(long l)
      {
              if (l >= 1000000000000000000L) return 19;
              if (l >= 100000000000000000L) return 18;
              if (l >= 10000000000000000L) return 17;
              if (l >= 1000000000000000L) return 16;
              if (l >= 100000000000000L) return 15;
              if (l >= 10000000000000L) return 14;
              if (l >= 1000000000000L) return 13;
              if (l >= 100000000000L) return 12;
              if (l >= 10000000000L) return 11;
              if (l >= 1000000000L) return 10;
              if (l >= 100000000L) return 9;
              if (l >= 10000000L) return 8;
              if (l >= 1000000L) return 7;
              if (l >= 100000L) return 6;
              if (l >= 10000L) return 5;
              if (l >= 1000L) return 4;
              if (l >= 100L) return 3;
              if (l >= 10L) return 2;
              return 1;
      }
      static void sort2D(int[][] Arr){Arrays.sort(Arr, (a, b) -> Double.compare(a[0], b[0]));}
      public static void main(String[] args) throws IOException
      {
          BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
          if (System.getProperty("ONLINE_JUDGE") == null)
          {
              try 
              {
                  in = new BufferedReader(new FileReader("input.txt"));
                  System.setOut(new PrintStream(new FileOutputStream("output.txt")));
              }
              catch (Exception e) {
                  //System.out.println("Exception");
              }
          }
          int T = Integer.parseInt(in.readLine());
          while( T -- > 0)
          {
              int N = Integer.parseInt(in.readLine());
              String lines = in.readLine();
              String[] strs = lines.trim().split("\\s+");
              int[] ar = new int[N];
              for(int i = 0; i < N; i++)
              {
                  ar[i] = Integer.parseInt(strs[i]);
              }
              int h = 1;
              if(ar[0] == 1)
                  h = 2;
              if(N > 1)
              {
                  for(int i = 1; i < N; i++)
                  {
                      if(ar[i-1]+ar[i] == 0)
                      {
                          // System.out.println("1");
                          h = -1;
                          break;
                      }
                      else if(ar[i] == 1)
                      {
                          // System.out.println("2");
                          h++;
                          if(ar[i-1] == 1)
                          {
                              // System.out.println("3");
                              h+=4;
                              // i++;
                          }
                      }
                  }
              }
              System.out.println(h);
          }
      }
  }