answer.code: In function ‘int main()’:
answer.code:2:13: error: expected unqualified-id before ‘long’
    2 | #define int long long
      |             ^~~~
answer.code:18:14: note: in expansion of macro ‘int’
   18 |       int a, int b; cin>>a>>b;
      |              ^~~
answer.code:18:29: error: ‘b’ was not declared in this scope
   18 |       int a, int b; cin>>a>>b;
      |                             ^
answer.code:25:20: error: ‘st’ was not declared in this scope; did you mean ‘sz’?
   25 |       if(!sz[i]) { st.insert(i); q.push(i); vis[i] = 1;}
      |                    ^~
      |                    sz