Try 1 => A = 1, B = 2, C = 3 ; X = 1, Y = 0, Z = 1  => not good
Try 2 => A = 1, B = 1, C = 1 ; X = 10, Y = 5, Z = 4 => good enough

Try 1 => A = 1.4, B = 2.6, C = 3.8 ; X = 10, Y = 5, Z = 3.9 => lucky!!!

...
Try 10 => A = 1.4, B = 2.6, C = 3.8 ; X = 10, Y = 5, Z = 3.9 => took a while!!!