/in/foo.cc:2:28: error: conflicting declaration 'char** arg'
 int main(int arg,char* arg[]){
                            ^
/in/foo.cc:2:14: note: previous declaration as 'int arg'
 int main(int arg,char* arg[]){
              ^~~
/in/foo.cc:2:5: warning: 'int main(int)' takes only zero or two arguments [-Wmain]
 int main(int arg,char* arg[]){
     ^~~~