/in/foo.cc: In function 'void work(int)':
/in/foo.cc:61:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j,k,l,r,ans;
        ^
/in/foo.cc:61:10: warning: unused variable 'k' [-Wunused-variable]
  int i,j,k,l,r,ans;
          ^
/in/foo.cc: In function 'void building(int)':
/in/foo.cc:86:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j,k;
        ^