How many carbon hydrogen and oxygen molecules is photosynthesis composed of?

None, because 'photosynthesis' is not a molecular compound. It's a biochemical pathsway of many consecutive reactions resulting in the forming of sugar C6H12O6.

(b.t.w. this is 6 C atoms, not molecules, and 12 H atoms and 6 O atoms in 1 (one) molecule of hexose sugar)