foo.c:1:1: warning: data definition has no type or storage class
    1 | n=int(input('n:'))
      | ^
foo.c:1:1: warning: type defaults to 'int' in declaration of 'n' [-Wimplicit-int]
foo.c:1:3: error: expected expression before 'int'
    1 | n=int(input('n:'))
      |   ^~~
foo.c:1:13: warning: multi-character character constant [-Wmultichar]
    1 | n=int(input('n:'))
      |             ^~~~
foo.c:3:7: warning: multi-character character constant [-Wmultichar]
    3 | print('P:',P)
      |       ^~~~

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