## 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:


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`).

The input will always be valid (i.e. there will be a molecule with that mass). If the input is ambiguous (multiple molecules have the same mass), you must only output one of the molecules. How you choose this molecule is up to you.

## 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:


## More Examples

    Input -> Output

    28.054 -> C2H4
    74.079 -> C3H6O2
    75.067 -> C2H5O2N
    18.015 -> H2O

## Winning

Shortest code in bytes wins.