/in/foo.cc: In function 'int main()':
/in/foo.cc:54:18: error: 'rean_ans' was not declared in this scope
  sort(real_ans+1,rean_ans+Max+1);
                  ^~~~~~~~
/in/foo.cc:54:18: note: suggested alternative: 'real_ans'
  sort(real_ans+1,rean_ans+Max+1);
                  ^~~~~~~~
                  real_ans