foo.cc:3:16: error: 'a' was not declared in this scope
    3 | int palindrome(a,x)
      |                ^
foo.cc:3:18: error: 'x' was not declared in this scope
    3 | int palindrome(a,x)
      |                  ^
foo.cc:3:19: error: expression list treated as compound expression in initializer [-fpermissive]
    3 | int palindrome(a,x)
      |                   ^
foo.cc:15:1: error: expected declaration before '}' token
   15 | }
      | ^
foo.cc: In function 'int main()':
foo.cc:27:37: error: 'palindrome' cannot be used as a function
   27 |                         a=palindrome(a,x);
      |                           ~~~~~~~~~~^~~~~

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