$a=$(Get-Content "C:\users\usacys\Desktop\test.txt")
[int]$x,[int]$y,[int]$z,[int]$n=$a[135,227,578,892]
$x + $y
$x * $z
$X - $Z
($x + $y)*($z-$x)+($y+$z)
$a.Length - ($n)