Compilare: user.c:2:1: warning: return type defaults to ‘int’ [enabled by default] main() ^ user.c: In function ‘main’: user.c:4:13: warning: unused variable ‘cmmdc’ [-Wunused-variable] int a,b,cmmdc; ^ user.c:6:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a); ^ user.c:8:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&b); ^