2018. A OK

#include <iostream>
#include <bits/stdc++.h>
using namespace std;

void numberToLetters(int n)
{
    char str[11];
    int i = 0;
    while (n > 0) {
        int remainder = n % 26;

        if (remainder == 0) {
            str[i++] = 'Z';
            n = (n / 26) - 1;
        }
        else
        {
            str[i++] = (remainder - 1) + 'A';
            n = n / 26;
        }
    }
    str[i] = '\0';

    reverse(str, str + strlen(str));
    cout << str << endl;

    return;
}

int lettersToNumber(string inputString)
{

    int result = 0;
    for (const auto& c : inputString)
    {
        result *= 26; // 0  // 26 //
        result += c  - 'A' + 1; //A // A
        // AAC

      //  cout << "c: " << c << endl;
    }

    return result;
}

int main()
{
    int broiTestove =0;
cin >> broiTestove;
cin.ignore();
string input;

while(broiTestove--)
{
  getline(cin, input);

  char check = input.at(0);
  int checkInt = check;

  if(checkInt>57)
    {
   //   cout << "chars"<< endl;
    int result = lettersToNumber(input);
    cout << result << endl;
    }
  else  {
    int currentNum = atoi(input.c_str());
    numberToLetters(currentNum);
        }
}

return 0;

}