Treatment of buta-\(1,3\)-diyne with \(\mathrm{NaNH_2}\) (2 equivalents), followed by reaction with excess of trans-\(\mathrm{CH_3-CH=CH-CH_2-Br}\) gives \(X\) as the major product. The maximum number of carbon atoms that are collinear (in a straight line) in \(X\) is ____.