Memory not freed:
-----------------
   Address     Size     Caller
0x082ae560      0xe  at ../../../AndreaSterbini/modulo4.c:60
0x082ae578     0x31  at ../../../AndreaSterbini/modulo4.c:60
0x082ae5b0      0x7  at ../../../AndreaSterbini/modulo4.c:60
0x082ae5c0     0x4f  at ../../../AndreaSterbini/modulo4.c:60