/in/foo.cc: In function 'std::pair<long long int, long long int> cal(long long int, long long int)':
/in/foo.cc:17:60: error: could not convert '{((((l.std::pair<long long int, long long int>::first + r.std::pair<long long int, long long int>::first) + l.std::pair<long long int, long long int>::second) + r.std::pair<long long int, long long int>::second) + (x * r.std::pair<long long int, long long int>::first))}' from '<brace-enclosed initializer list>' to 'std::pair<long long int, long long int>'
   17 |         return {l.first+r.first+l.second+r.second+x*r.first};
      |                                                            ^
      |                                                            |
      |                                                            <brace-enclosed initializer list>