foo.cc: In function 'int main()':
foo.cc:8:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(i=1;i<=N;i++) scanf("%d",&e[i]);
                       ~~~~~^~~~~~~~~~~~
foo.cc:12:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d",&K);
         ~~~~~^~~~~~~~~
foo.cc:15:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d%d%d",&L,&R,&C);
             ~~~~~^~~~~~~~~~~~~~~~~~~
foo.cc:21:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d%d",&L,&R);
             ~~~~~^~~~~~~~~~~~~~