-----------+----------+------+
| +      | T            | b        | ?    |
| +      | T            | e        | ?    |
| +      | G            | b        | ?    |
| +      | G            | e        | ?    |
| +      | C            | b        | .    |
| +      | C            | e        | .    |
| +      | C            | h        | .    |
| +      | C            | m        | .    |
| +      | A            | a        | .    |
| +      | A            | b        | .    |
| +      | A            | e        | .   