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 Solution {
  
  	public static void main(String[] args) {
  		Scanner sc = new Scanner(System.in);
  		int t = sc.nextInt();
  		while(t-->0) {
  			int n = sc.nextInt();
  			int a[] = new int[n];
  			for(int i=0;i<n;i++) a[i] = sc.nextInt();
  			int ans = 1; boolean flag=true;int i=0;int j=0;
  			while(i<n) {
  				if(a[i]==1) {
  					ans+=1;
  					for(j=i+1;j<n;j++) {
  						if(a[j]==1) ans+=5;
  						else break;
  					}
  					i=j;
  				} else {
  					if(i+1<n && a[i+1]==0) {
  						flag=false;
  						break;
  					}
  					else i++;
  				}
  			}
  			if(flag==false) System.out.println("-1");
  			else System.out.println(ans);
  		}
  	}
  
  }
  