In file included from /usr/include/c++/13/unordered_map:37,
                 from answer.code:8:
/usr/include/c++/13/bits/c++0x_warning.h:32:2: error: #error This file requires compiler and library support for the ISO C++ 2011 standard. This support must be enabled with the -std=c++11 or -std=gnu++11 compiler options.
   32 | #error This file requires compiler and library support \
      |  ^~~~~
answer.code:22:29: warning: integer constant is so large that it is unsigned
   22 |                 else if(a==-9223372036854775808 && b==-1) cout<<"9223372036854775808\n";
      |                             ^~~~~~~~~~~~~~~~~~~
answer.code:22:17: warning: this decimal constant is unsigned only in ISO C90
   22 |                 else if(a==-9223372036854775808 && b==-1) cout<<"9223372036854775808\n";
      |                 ^~~~