Balanced Chemical Reactions For a chemical reaction represented by a string, verify that the chemical reaction is a balanced reaction (i.e. that we didn't somehow lose or gain an atom during reaction). If the reaction is balanced return true, otherwise return false. For example, for the hydrogen combustionreaction: '2 H2 + O2 -> 2 H2O' would output true because the number of atoms in the reactants match up with the number of atoms in the product. However, for the precipitation of silver-chloride: 'NaCl + AgNO3 -> NaNO3 + Ag' the output should be false because we're missing the chlorine atom in the products. The reactancts and products will always be separated by a right pointing arrow "->" and the individual molecules within the reactants/products are always separated by a "+" sign. Multiple molecules are represented by a number and space prefacing the molecule (e.g., "2 H20").
