运行 ID: 793

Main.cc: In function ‘int main()’:
Main.cc:3:2: error: ‘scanf’ was not declared in this scope
  scanf("%d",&n);
  ^~~~~
Main.cc:8:2: error: ‘printf’ was not declared in this scope
  printf("%d",sum);
  ^~~~~~
Main.cc:8:2: note: suggested alternative: ‘int’
  printf("%d",sum);
  ^~~~~~
  int