Because the only brainfuck instructions in your comment where a - which decrements and 20 +, each of which increments.
Mine echos the first two characters from stdin, because of the commas and dots.

it's been a long time since i looked at brainfuck, but i suspect that '+' denotes an increment, and '-' denotes a decrement, so we've got one decrement and 20 increments.

Just add // @TODO find out why this crashes our application sometimes to fix that issue