Error:
CH4 %2B Cl2 %3D CHCl3 %2B CH2Cl %2B CH3Cl %2B CCl4 %2B HCl
^Unexpected character ('%')CH4 %2B Cl2 %3D CHCl3 %2B CH2Cl %2B CH3Cl %2B CCl4 %2B HCl
^Unexpected character ('%')