You need to make 3 pies, one for NaCl, one for C6H12O6, and one for NaOH.
NaCl has two elements, Na (sodium) and Cl (chlorine).
C6H12O6 has three different elements, carbon (C), hydrogen (H), and oxygen (O).
NaOH has three elements, Na (sodium), O (oxygen), and H (hydrogen).