Main.cc: In function 'int main()':
Main.cc:13:18: error: invalid operands of types 'long long int*' and 'int' to binary 'operator*'
cout <<(a-1)*2;
^
Main.cc:9:15: warning: unused variable 'q' [-Wunused-variable]
long long q = 0;
^
Main.cc:17:13: error: expected '}' at end of input
return 0;
^