C=7
7¹=(....7)
7²=(....9)
7³=(....3)
7⁴=(....1)
7⁵=(....7)
se repeta din 4 in 4
124:4= 31 =>7¹²⁴=(.....7)
A=9
9¹=(....9)
9²=(....1)
9³=(.....9)
se repeta din 2 in 2
82:2= 41 =>9⁸² =(......9)
B=1
1⁵³ =1
(.....7)-(......9)-(.....1)= (....-2)-(....1)= -(.....1)