/in/foo.cc: In function 'void init(int, int)':
/in/foo.cc:11:37: error: 'scanf_s' was not declared in this scope
   scanf_s("%d%d", &person1, &person2);
                                     ^
/in/foo.cc: In function 'void answer(int)':
/in/foo.cc:34:37: error: 'scanf_s' was not declared in this scope
   scanf_s("%d%d", &person1, &person2);
                                     ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:46:30: error: 'scanf_s' was not declared in this scope
  scanf_s("%d%d%d", &n, &m, &p);
                              ^