/in/foo.cc: In function 'void ACM_fail()':
/in/foo.cc:52:18: warning: unused variable 'k' [-Wunused-variable]
  int h=0,t=1,i,j,k;
                  ^
/in/foo.cc: In function 'void work()':
/in/foo.cc:79:10: warning: unused variable 'k' [-Wunused-variable]
  int i,j,k;
          ^