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: #include <bits/stdc++.h>
  using namespace std;
  long long int powerMod(long long int a, long long int b, long long int m) {
    long long int result = 1;
    while (b > 0) {
      if (b & 1) result = (result * a) % m;
      a = (a * a) % m;
      b /= 2;
    }
    return result;
  }
  long long int power(long long int a, long long int b) {
    long long int result = 1;
    while (b > 0) {
      if (b & 1) result *= a;
      a *= a;
      b /= 2;
    }
    return result;
  }
  long long int gcd(long long int a, long long int b) {
    return b ? gcd(b, a % b) : a;
  }
  int main() {
    cin.tie(0)->sync_with_stdio(0);
    int t;
    cin >> t;
    while (t--) {
      long long int n;
      cin >> n;
      vector<long long int> arr;
      bool ok = true;
      long long int prev = -1;
      for (int i = 0; i < n; ++i) {
        long long int x;
        cin >> x;
        if (i == 0)
          prev = x;
        else {
          if (x == 0 && prev == 0) ok = false;
          prev = x;
        }
        arr.push_back(x);
      }
      long long int ans = 1;
      if (ok) {
        for (int i = 0; i < n; ++i) {
          if (i == 0) {
            if (arr[i]) ans += 1;
          } else {
            if (arr[i]) {
              if (arr[i - 1])
                ans += 5;
              else
                ans += 1;
            }
          }
        }
        cout << ans << "\n";
      } else {
        cout << -1 << "\n";
      }
    }
  }
  