/in/foo.c: In function 'main':
/in/foo.c:19:2: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
  else
  ^~~~
/in/foo.c:24:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'else'
   printf("%d",sum%p);
   ^~~~~~
/in/foo.c:5:16: warning: unused variable 'j' [-Wunused-variable]
  int n,sum=0,i,j;
                ^