answer.code: In function ‘void solve()’:
answer.code:124:45: error: call of overloaded ‘abs(std::vector<std::pair<long long int, long long int> >::size_type)’ is ambiguous
  124 |   if(ans==0 && (o.size()+x.size()<n*n || abs(o.size()-x.size())>1))
      |                                          ~~~^~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/13/cstdlib:79,
                 from /usr/include/c++/13/ext/string_conversions.h:43,
                 from /usr/include/c++/13/bits/basic_string.h:4097,
                 from /usr/include/c++/13/string:54,
                 from /usr/include/c++/13/bits/locale_classes.h:40,
                 from /usr/include/c++/13/bits/ios_base.h:41,
                 from /usr/include/c++/13/ios:44,
                 from /usr/include/c++/13/ostream:40,
                 from /usr/include/c++/13/iostream:41,
                 from answer.code:1:
/usr/include/stdlib.h:840:12: note: candidate: ‘int abs(int)’
  840 | extern int abs (int __x) __THROW __attribute__ ((__const__)) __wur;
      |            ^~~
In file included from /usr/include/c++/13/cstdlib:81:
/usr/include/c++/13/bits/std_abs.h:79:3: note: candidate: ‘constexpr long double std::abs(long double)’
   79 |   abs(long double __x)
      |   ^~~
/usr/include/c++/13/bits/std_abs.h:75:3: note: candidate: ‘constexpr float std::abs(float)’
   75 |   abs(float __x)
      |   ^~~
/usr/include/c++/13/bits/std_abs.h:71:3: note: candidate: ‘constexpr double std::abs(double)’
   71 |   abs(double __x)
      |   ^~~
/usr/include/c++/13/bits/std_abs.h:61:3: note: candidate: ‘long long int std::abs(long long int)’
   61 |   abs(long long __x) { return __builtin_llabs (__x); }
      |   ^~~
/usr/include/c++/13/bits/std_abs.h:56:3: note: candidate: ‘long int std::abs(long int)’
   56 |   abs(long __i) { return __builtin_labs(__i); }
      |   ^~~