answer.code: In lambda function:
answer.code:85:24: error: conflicting declaration ‘auto _’
   85 |           const auto &[_, x2, y2] = ret[j];
      |                        ^
answer.code:84:24: note: previous declaration as ‘std::tuple_element<0, const std::tuple<int, int, int> >::type& _’
   84 |           const auto &[_, x1, y1] = ret[i];
      |                        ^
answer.code:86:31: error: use of ‘x2’ before deduction of ‘auto’
   86 |           if (x1 == a && a == x2 || y1 == b && b == y2) fallen = true;
      |                               ^~
answer.code:86:53: error: use of ‘y2’ before deduction of ‘auto’
   86 |           if (x1 == a && a == x2 || y1 == b && b == y2) fallen = true;
      |                                                     ^~
answer.code: In function ‘int32_t main()’:
answer.code:65:12: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   65 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~