foo.c: In function 'CF':
foo.c:64:7: warning: unused variable 'i' [-Wunused-variable]
   int i;
       ^
foo.c: In function 'main':
foo.c:10:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d%d%d",&x1,&n1,&k);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务