/in/foo.c: In function 'main':
/in/foo.c:5:28: warning: unused variable 'sum2' [-Wunused-variable]
  int n,sum=0,avg,num=0,i,j,sum2=0;
                            ^~~~
/in/foo.c:5:26: warning: unused variable 'j' [-Wunused-variable]
  int n,sum=0,avg,num=0,i,j,sum2=0;
                          ^