Which nitrogenous bases form complimentary pairs?

In DNA (Deoxtribonucleic acid) there are 4 bases and the pairning rules are as follows: Adenine-Thymine and the other is Guanine-Cytosine However in RNA (Ribonucleic Acid) the bases are different and thus the base pairing-the "complimentary pairs" are Adenine-Uracil and Guanine-Cytosine