foo.c: In function 'Unique':
foo.c:41:6: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   if(a1[f]=-10000000)
      ^~
foo.c: In function 'main':
foo.c:8:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n1,&n2);
  ^~~~~~~~~~~~~~~~~~~~~
foo.c:12:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&x1);
   ^~~~~~~~~~~~~~~
foo.c:17:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&x2);
   ^~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务