/in/foo.cc:3:0: warning: ignoring #pragma optimize  [-Wunknown-pragmas]
 #pragma optimize(3, "Ofast", "inline")
 
/in/foo.cc: In function 'int main()':
/in/foo.cc:61:15: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
     write(ans);
               ^