/in/foo.cc: In function 'int main()':
/in/foo.cc:6:24: warning: unused variable 'j' [-Wunused-variable]
  int i,ans=0,sum=0,num,j,k=0;
                        ^
/in/foo.cc:6:26: warning: unused variable 'k' [-Wunused-variable]
  int i,ans=0,sum=0,num,j,k=0;
                          ^