Count all configurational stereoisomers of 1,2,3-trimethylcyclohexane (enantiomers are counted separately and a meso form is counted once; conformers are not counted). Give the answer as an integer.

Numerical answer type, tolerance 0.5.

Answer: 4

Label each methyl up or down (8 combinations). Rotating the molecule about an in-plane axis reverses the ring order and flips faces, so (a,b,c) is the same as (not c, not b, not a), giving 4 stereoisomers. The all-cis (UUU) and the (UDU) forms are meso (mirror plane through C2), while (UUD) and its mirror image (DUU) are an enantiomeric pair. Total = 4.

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