come si fa 99999 x 9999 ?

9 9 9 9 9 9 9 9 9 x = 1 8 9 8 9 8 9 8 9 8 1 8 9 8 9 8 9 8 9 8 1 8 9 8 9 8 9 8 9 8 1 8 9 8 9 8 9 8 9 8 1 1 2 3 3 2 1 1 0 0 0 9 8 9 9 9
x