/in/foo.cc: In function 'int main()':
/in/foo.cc:8:7: warning: unused variable 'k' [-Wunused-variable]
  char k,d[100];
       ^
/in/foo.cc:9:14: warning: unused variable 'aa' [-Wunused-variable]
  int a=0,b=0,aa=0,bb=0,i=0;
              ^
/in/foo.cc:9:19: warning: unused variable 'bb' [-Wunused-variable]
  int a=0,b=0,aa=0,bb=0,i=0;
                   ^