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.util.*;
  public class sol2 {
  
      public static void main(String[] args) {
          Scanner scan = new Scanner(System.in);
          int t = scan.nextInt();
          int dead_flag=0;
          for (int i=0; i<t; i++){
              int height =1;
              int n = scan.nextInt();
              dead_flag=0;
              int curr=0, prev=-1;
              
              for (int j=0; j<n; j++){
                  curr = scan.nextInt();
                  if (curr==0 && prev==0){
                      
                      dead_flag = 1;
                      
                  }
                  else if (curr==1 && prev!=1){
                      height+=1;
                  }
                  else if (curr+prev==2){
                      height+=5;
                  }
                  prev = curr;
              }
              if (dead_flag==0)
                  System.out.println(height);
              else if (dead_flag==1)
                  System.out.println("-1");
          }
      }
  }