description: You are given a digital clock with n digits. Each digit shows an integer from 0 to 9, so the whole clock shows an integer from 0 to 10^n-1. The clock will show leading zeroes if the number is smaller than 10^{n-1}.
  
  You want the clock to show 0 with as few operations as possible. In an operation, you can do one of the following: 
  
    * decrease the number on the clock by 1, or 
    * swap two digits (you can choose which digits to swap, and they don't have to be adjacent). 
  
  
  
  Your task is to determine the minimum number of operations needed to make the clock show 0.
  
  Input
  
  Each test contains multiple test cases. The first line contains the number of test cases t (1 ≤ t ≤ 10^3).
  
  The first line of each test case contains a single integer n (1 ≤ n ≤ 100) — number of digits on the clock.
  
  The second line of each test case contains a string of n digits s_1, s_2, …, s_n (0 ≤ s_1, s_2, …, s_n ≤ 9) — the number on the clock.
  
  Note: If the number is smaller than 10^{n-1} the clock will show leading zeroes.
  
  Output
  
  For each test case, print one integer: the minimum number of operations needed to make the clock show 0.
  
  Example
  
  Input
  
  
  7
  3
  007
  4
  1000
  5
  00000
  3
  103
  4
  2020
  9
  123456789
  30
  001678294039710047203946100020
  
  
  Output
  
  
  7
  2
  0
  5
  6
  53
  115
  
  Note
  
  In the first example, it's optimal to just decrease the number 7 times.
  
  In the second example, we can first swap the first and last position and then decrease the number by 1.
  
  In the third example, the clock already shows 0, so we don't have to perform any operations.
solution: from collections import deque
  import heapq
  from math import sqrt
  import operator
  from operator import itemgetter
  import sys
  
  import copy
  
   
  inf_var = 0
  if inf_var == 1:
      inf = open('input.txt', 'r')
  else:
      inf = sys.stdin
   
  input = inf.readline
  # sys.stdout = open('output.txt', 'w')
   
  def read_one_int():
      return int(input().rstrip('\n'))
  
  
  def read_one_float():
      return float(input().rstrip('\n'))
   
   
  def read_list_of_ints():
      res = [int(val) for val in (input().rstrip('\n')).split(' ')]
      return res
   
  def read_str():
      return input().rstrip()
  
  
  def count_operations(n, cur_str):
      non_zero = 0
      dig_sum = 0
  
      for ch in cur_str:
          if ch != '0':
              non_zero += 1
              dig_sum += int(ch)
  
      if not non_zero:
          print(0)
          return
  
      res = dig_sum + non_zero
  
      if cur_str[-1] != '0':
          res -= 1
  
      print(res)
  
  
  def main():
      tests = read_one_int()
  
      for _ in range(tests):
          n = read_one_int()
          cur_str = read_str()
  
          count_operations(n, cur_str)
  
  
  if __name__== '__main__':
      main()
  