read "%d+" ↔ O "l" = O "k" = O "j" = [
read "%d+" ↔ O l - "c" = O k - "b" = O j - "a" = [
read "%d+" ↔ O l - z = O k - y = O j - x = [
read "%d+" ↔ O l - Z = O k - Y = O j - X = [
a y Z * Y z * - * b z X * Z x * - * c x Y * X y * - * + + 6 //