foo.c: In function 'main':
foo.c:14:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n,&N);
  ^~~~~~~~~~~~~~~~~~~~
foo.c:15:19: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  for(i=0;i<n;i++) scanf("%d",&a[i]);
                   ^~~~~~~~~~~~~~~~~
foo.c:16:19: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  for(i=0;i<N;i++) scanf("%d",&b[i]);
                   ^~~~~~~~~~~~~~~~~