Draw the Lewis structure of CO2 in its best resonance form. There is no O–O bond in this compound.

These are the directions: I came up with this answer,

O(three lone pairs) (neg 1 formal charge) single bond to C (one lone pair neg 1 formal charge) double bonded to O with two lone pairs

After showing this answer I am told:

Your response is incorrect (1 try).

The sum of the formal charges of the atoms in your structure should equal the total charge given for the compound.

I am lost.. any help?

My only thought is I may have to do ::O=C=O:: or something like that? Thanks!