private static void tryKeyAt(char ch, int row, int col) {
String cipherText = cipherTexts.get(row);
printChangesInCell(-1, col);
key[col] = CryptoHelpers.xorCharAt(cipherText, ch, col);
printChangesInCell(-1, col);
for (int i = 0; i < possibleLetters.length; i++) {
printChangesInCell(i, col);
resultLetters[i][col] = CryptoHelpers.xorCharAt(cipherTexts.get(i), key[col], col);
printChangesInCell(i, col);
}
}
