Hello guys.. i read the tutorial and the comments and i can't get it sadly so far.. so if anyone can give me a hint for this problem Magic Formula gonna be grateful too much. The thing that i can't get in the tutorial is the flipping of (i % 1) ^ (i % 2) ^ ..... (i % n) to (1 % i) ^ (2 % i) ^ ..... (3 % i) ... (n % i).. and WHY would he do so.. Thanks in advance.