Human Body and RNA/DNA
A quick search would tell you what the 4 nucleobases for RNA are made of:

Uracil: 4 Carbon 4 Hydrogen 2 Nitrogen 2 Oxygen



Adenine: 5 Carbon 5 Hydrogen 5 Nitrogen



Guanine: 5 Carbon 5 Hydrogen 5 Nitrogen 1 Oxygen



Cytosine: 4 Carbon 5 Hydrogen 3 Nitrogen 1 Oxygen