Compilare: main.cpp: In function 'int cmmdc(int, int)': main.cpp:21:11: warning: left operand of comma operator has no effect [-Wunused-value] 21 | return("%d", a); | ^~~~ main.cpp: In function 'int main()': main.cpp:26:15: warning: unused variable 'k' [-Wunused-variable] 26 | int a,b,d,k; | ^ main.cpp: In function 'int cmmdc(int, int)': main.cpp:10:15: warning: control reaches end of non-void function [-Wreturn-type] 10 | printf("-1"); | ~~~~~~^~~~~~