answer.code: In function ‘void solve()’:
answer.code:99:5: error: ‘function’ was not declared in this scope
   99 |     function<void(int, CT)> dfs = [&](int u, CT xx)
      |     ^~~~~~~~
answer.code:99:5: note: ‘std::function’ is only available from C++11 onwards
answer.code:99:26: error: expression list treated as compound expression in functional cast [-fpermissive]
   99 |     function<void(int, CT)> dfs = [&](int u, CT xx)
      |                          ^
answer.code:99:14: error: expected primary-expression before ‘void’
   99 |     function<void(int, CT)> dfs = [&](int u, CT xx)
      |              ^~~~
answer.code:145:26: error: ‘to’ does not name a type; did you mean ‘tm’?
  145 |                 for(auto to : mp[u])
      |                          ^~
      |                          tm
answer.code:153:18: error: expected ‘;’ before ‘}’ token
  153 |                 }
      |                  ^
      |                  ;
  154 |             }
      |             ~     
answer.code:154:13: error: expected primary-expression before ‘}’ token
  154 |             }
      |             ^
answer.code:153:18: error: expected ‘;’ before ‘}’ token
  153 |                 }
      |                  ^
      |                  ;
  154 |             }
      |             ~     
answer.code:154:13: error: expected primary-expression before ‘}’ token
  154 |             }
      |             ^
answer.code:153:18: error: expected ‘)’ before ‘}’ token
  153 |                 }
      |                  ^
      |                  )
  154 |             }
      |             ~     
answer.code:145:20: note: to match this ‘(’
  145 |                 for(auto to : mp[u])
      |                    ^
answer.code:154:13: error: expected primary-expression before ‘}’ token
  154 |             }
      |             ^
answer.code:158:17: error: ‘dfs’ was not declared in this scope; did you mean ‘ffs’?
  158 |                 dfs(u, qm);
      |                 ^~~
      |                 ffs
answer.code:167:18: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘long long int’ [-Wformat=]
  167 |         printf("%d\n", ans);
      |                 ~^     ~~~
      |                  |     |
      |                  int   long long int
      |                 %lld