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: import java.nio.file.FileAlreadyExistsException;
  import java.util.Scanner;
  
  public class Main {
      public static void main(String[] args) {
          Scanner scanner = new Scanner(System.in);
          int cases = Integer.parseInt(scanner.nextLine());
          cases: while (cases-- > 0) {
              int days = Integer.parseInt(scanner.nextLine());
              String data = scanner.nextLine();
              int height = 1;
              boolean lastState = false;
              for (int i = 0; i < (days << 1); i += 2) {
                  if (data.charAt(i) == '1') {
                      if (i != 0 && lastState) {
                          height += 5;
                      } else {
                          height += 1;
                      }
                      lastState = true;
                  } else {
                      if (i != 0 && !lastState) {
                          System.out.println(-1);
                          continue cases;
                      }
                      lastState = false;
                  }
              }
              System.out.println(height);
          }
      }
  }
  