## Challenge Given the high resolution molecular mass of an organic molecule, output the molecule's molecular formula. ## Explanation The input will be a single number to three decimal places of precision, the relative molecular mass of the molecule. Here, the molecular mass is defined as the sum of the masses of the atoms in the compound. Since you only are finding the molecular formulae of organic compounds, the atomic masses you need to know are: - **C**, Carbon: 12.011 - **H**, Hydrogen: 1.008 - **O**, Oxygen: 15.999 - **N**, Nitrogen: 14.007 Your formula should only ever contain carbon, hydrogen, oxygen or nitrogen. When writing the formula, it should take the form: CaHbOcNd Where the elements must be in that order (`C -> H -> O -> N`, so `C2O8N4H6` should be `C2H6O8N4`) and `a`, `b`, `c` and `d` are numbers of the preceding element in the molecule (i.e. `C2` means that there are two carbon atoms in the molecule). If `a`, `b`, `c` or `d` are zero, that element should not be included in the formula (e.g. `C2H6O2N0` should be `C2H6O2`). Finally, if `a`, `b`, `c` or `d` are one, you should not include the number in the formula (e.g. `C1H4` should be `CH4`). ## Worked Example Suppose the input is `180.156`, there is only one combination of the elements which can have this molecular mass: 12.011*6 + 1.008*12 + 15.999*6 + 14.007*0 = 180.156 So there are: - 6 Carbons - 12 Hydrogens - 6 Oxygens - 0 Nitrogens Therefore, your output should be: C6H12O6 ## More Examples ### Ethene **Input:** 28.054 **Output:** C2H4 ### Propanoic Acid **Input:** 74.079 **Output:** C3H6O2 ### Glycine **Input:** 75.067 **Output:** C2H5O2N ### Water **Input:** 18.015 **Output:** H2O ## Winning Shortest code in bytes wins.