Compilare: user.c: In function ‘multiply’: user.c:45: warning: unused variable ‘mod’ user.c: In function ‘main’: user.c:103: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result user.c:104: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result user.c:105: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c: In function ‘multiply’: user.c:44: warning: ‘i’ may be used uninitialized in this function