n:2=C1 rest 1=>n=2×C1+1=>n-1=2×C1=>n-1€(apartina)M2
n:3=C2rest 1=> n=3×C2+1=> n-1=3×C2=>n-1€M3
n:4=C3 rest 1=> n=4×C3+1=>n-1=4×C3=>n-1€M4 din toate astea =>n-1€M [2,3,4]
Acum descompunem nr in numere prime
2=2
3=3
4=2 la puterea a 2
c.m.m.m.c.=2 la puterea a 2 ×3=12
n-1€M12
n-1=12
n=12-1
n=11
