What is the oxidization number of KHCO3

the answer is given and it states

each O has an oxidation number of ­2, using Rule #5; K has an oxidation number of +1, using Rule #3; H has an oxidation number of +1, using Rule #4; and Br has an oxidation number of +7, using Rule #8

however the answer I got was K=+1 H=+1 C=+4 O=-2

Im not sure if Im wrong or the answer that was given was wrong?? it says Br and Br wasnt even in the formula?!?

K=+1 H=+1 C=+4 O=-2 is correct.

Br has nothing to do with it.