foo.c: In function 'cs':
foo.c:10:14: warning: unused variable 'c' [-Wunused-variable]
  int a=i,b=0,c;
              ^
foo.c:10:6: warning: unused variable 'a' [-Wunused-variable]
  int a=i,b=0,c;
      ^
foo.c: In function 'ss':
foo.c:34:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
foo.c: In function 'main':
foo.c:38:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ^~~~~~~~~~~~~~

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