Write the IUPAC name of the compound shown, choosing the longest chain that contains the double bond and giving the double bond the lowest locant. Add together the locants of the double bond and of every substituent (each substituent counted once). Give the sum as an integer.

Numerical answer type, tolerance 0.5.

Answer: 10

The compound is 4-ethyl-2,3-dimethylhex-1-ene. Locants: double bond 1, methyl groups 2 and 3, ethyl group 4. The sum is 1 + 2 + 3 + 4 = 10.