a=1:
=> d=4
Daca b=0 => c=5
Daca b=2 => c=3
Daca b=3 => c=2
Daca b=5 => c=0
a=2:
=> d=3
Daca b=0 => c=5
Daca b=1 => c=4
Daca b=4 => c=1
Daca b=5 => c=0
a=3:
=> d=2
Daca b=0 => c=5
Daca b=1 => c=4
Daca b=4 => c=1
Daca b=5 => c=0
a=4:
=> d=1
Daca b=0 => c=4
Daca b=2 => c=3
Daca b=3 => c=2
Daca b=5 => c=0
a=5:
=> d=0
Daca b=1 => c=4
Daca b=2 => c=3
Daca b=3 => c=2
Daca b=4 => c=1
Deci sunt 5*4=20 astfel de numere (se pot determina prin inlocuirea cifrelor gasite in fiecare caz in parte).
