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;
  inline int read() {
    int x = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9') {
      f = ch == '-' ? -1 : f;
      ch = getchar();
    }
    while (ch >= '0' && ch <= '9') {
      x = (x << 1) + (x << 3) + (ch ^ 48);
      ch = getchar();
    }
    return x * f;
  }
  void write(int x) {
    if (x < 0) {
      x = -x;
      putchar('-');
    }
    if (x > 9) write(x / 10);
    putchar(x % 10 + 48);
  }
  int n, t;
  int a[105];
  int main() {
    t = read();
    while (t-- > 0) {
      n = read();
      int res = 1;
      for (int i = 1; i <= n; ++i) a[i] = read();
      for (int i = 1; i <= n; ++i) {
        if (a[i] == 1 && a[i - 1] == 1)
          res += 5;
        else if (a[i] == 1)
          res++;
        else if (a[i] == 0 && a[i - 1] == 0 && i != 1) {
          res = -1;
          break;
        }
        if (res <= 0) {
          res = -1;
          break;
        }
      }
      write(res), putchar('\n');
    }
    return 0;
  }
  