+-----------------+
|1 + 1 + 1 + 1 + 1|
|1 + 1 + 1 + 1 + 1|
|1 + 1x0 + 1 = ?  |
+-----------------+

Determine the number that will replace the mark of interrogation, given that it is NOT 12.

Notes:

1. All the calculations are in the decimal (base 10) system. Calculations done in non-decimal system is NOT permissible.
2. Although this puzzle is in "tricks" category, some amount of logical thinking must be enunciated while solving this problem.