#include <iostream>
using namespace std;
int main()
{
  int testCases, amountOfNumbers;
  string text;
  cin >> testCases;
  while (testCases--)
  {
    cin >> amountOfNumbers >> text;
    int result = 1;
    int temp = 0;
    for (int i = 0; i < text.length(); i++)
    {
      if (text[i] == '?' && i > 0)
      {
        result *= 10;
      }
      else if (text[i] == '?' && i == 0)
      {
        result *= 9;
      }
      else if (text[i] != '?')
      {
        temp++;
      }
    }
    if (temp == amountOfNumbers)
    {
      result = 1;
      cout << result << endl;
      temp = 0;
    }
    else
    {
      cout << result << endl;
    }
  }
}

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NAozIDEyPwo1IDE/Mj8zCjMgMTIzCjMgPzIzCg==

4
3 12?
5 1?2?3
3 123
3 ?23