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.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.util.StringTokenizer;
   
  public class taska {
      public static void main(String[] args) {
          FastScanner in = new FastScanner();
          PrintWriter out = new PrintWriter(System.out);
          int tt = in.nextInt();
          while (tt-- > 0) {
              int n = in.nextInt();
              int a[] = new int[n];
              for (int i = 0; i < n; i++) a[i] = in.nextInt();
              int h = 1;
              boolean alive = true;
              for (int i = 0; i < n; i++) {
                  if (a[i] == 0) {
                      if (i > 0 && a[i - 1] == 0) {
                          alive = false;
                      }
                  } else {
                      if (i > 0 && a[i - 1] == 1) {
                          h += 5;
                      } else {
                          h++;
                      }
                  }
              }
              out.println(alive ? h : -1);
          }
          out.flush();
      }
   
      static class FastScanner {
          BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
          StringTokenizer st = new StringTokenizer("");
          String next() {
              while (!st.hasMoreTokens()) {
                  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()); }
          float nextFloat() { return Float.parseFloat(next()); }
          double nextDouble() { return Double.parseDouble(next()); }
      }
  }