[Ruff]

left  = 1*x[1] + 2*x[2] + 3*x[3] + 4*x[4] + 5*x[5];
right = 1*x[6] + 2*x[7] + 3*x[8] + 4*x[9] + 5*x[10];

diff = left - right;
index = diff < 0 ? -diff : 5 + diff;

return index;