foo.c:8:12: error: unknown type name 'item'
    8 | int maxone(item serial[],int n);
      |            ^~~~
foo.c:9:14: error: unknown type name 'item'
    9 | void counter(item serial[],int n);
      |              ^~~~
foo.c:10:12: error: unknown type name 'item'
   10 | void input(item serial[],int n);
      |            ^~~~
foo.c: In function 'main':
foo.c:14:2: error: unknown type name 'item'; use 'struct' keyword to refer to the type
   14 |  item serial[20000];
      |  ^~~~
      |  struct 
foo.c:16:2: warning: implicit declaration of function 'input' [-Wimplicit-function-declaration]
   16 |  input(serial,n);
      |  ^~~~~
foo.c:17:2: warning: implicit declaration of function 'counter' [-Wimplicit-function-declaration]
   17 |  counter(serial,n);
      |  ^~~~~~~
foo.c:18:6: warning: implicit declaration of function 'maxone' [-Wimplicit-function-declaration]
   18 |  max=maxone(serial,n);
      |      ^~~~~~
foo.c: At top level:
foo.c:22:12: error: unknown type name 'item'
   22 | int maxone(item serial[],int n)
      |            ^~~~
foo.c:33:14: error: unknown type name 'item'
   33 | void counter(item serial[],int n)
      |              ^~~~
foo.c:47:12: error: unknown type name 'item'
   47 | void input(item serial[],int n)
      |            ^~~~
foo.c: In function 'main':
foo.c:15:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   15 |  scanf("%d",&n);
      |  ^~~~~~~~~~~~~~

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