foo.c:2:1: warning: data definition has no type or storage class
    2 | n=int(input())
      | ^
foo.c:2:1: warning: type defaults to 'int' in declaration of 'n' [-Wimplicit-int]
foo.c:2:3: error: expected expression before 'int'
    2 | n=int(input())
      |   ^~~

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