C = X * b
C - b = Y * (A-1)
C - b - (A-1) = Z * (b-1)
C = 0 mod b
C - b = 0 mod (A-1)
C - b - (A-1) = 0 mod (b-1)
b >= A
C = 0 mod b
C = A mod (b-1)
C=100, A=5
b=1:
b=2:
b=4:
b=5:
b=10: C=50, 140, 230, 320, ...
b=20: C=100, 480, 860, 1240, ...
b=25: C=125, 725, 1325, 1925, ...
b=50: C=250, 2700, 5150, 7600, ...