#include <bits/stdc++.h>
using namespace std;
using namespace std;
int main() {
  string s;
  int n;
  char mozi[10][10] = {"abcde", "fghij", "klmno", "pqrst", "uvwxy", "z.?! "};
  bool flag = true;
  while (cin >> n) {
    for (int i = 0; i < n; i++) {
      cin >> s;
      if (s.size() % 2 == 1) {
        puts("NA");
        continue;
      } else {
        char str[201], kari[200];
        long int length = s.length();
        s.copy(str, length, 0);
        for (int i = 0; i < s.size(); i += 2) {
          if (0 <= (int)str[i] - 49 <= 5 && 0 <= (int)str[i + 1] - 49 <= 4)
            kari[i] = mozi[(int)str[i] - 49][(int)str[i + 1] - 49];
          else
            flag = false;
        }
        if (flag == true) {
          for (int i = 0; i < s.size(); i += 2) {
            cout << kari[i];
          }
        } else {
          cout << "NA";
        }
        puts("");
      }
    }
  }
  return 0;
}
