answer.code: In function ‘int hop(std::vector<std::vector<int> >&, vi&)’:
answer.code:9:19: error: ‘size’ was not declared in this scope
    9 | #define sz(x) int(size(x))
      |                   ^~~~
answer.code:27:14: note: in expansion of macro ‘sz’
   27 |         vi A(sz(g)), B(sz(btoa)), cur, next;
      |              ^~
answer.code: In function ‘int main()’:
answer.code:9:19: error: ‘size’ was not declared in this scope
    9 | #define sz(x) int(size(x))
      |                   ^~~~
answer.code:139:15: note: in expansion of macro ‘sz’
  139 |         cout<<sz(result)<<'\n';
      |               ^~
answer.code:140:18: warning: structured bindings only available with ‘-std=c++17’ or ‘-std=gnu++17’
  140 |         for(auto [x, y]: result) cout<<x<<' '<<y<<'\n';
      |                  ^