foo.cc: In function 'int isPrime(int)':
foo.cc:12:2: warning: no return statement in function returning non-void [-Wreturn-type]
   12 |  }
      |  ^
foo.cc: At global scope:
foo.cc:13:2: error: expected unqualified-id before 'return'
   13 |  return 1;
      |  ^~~~~~
foo.cc:14:3: error: expected unqualified-id before 'if'
   14 |   if(n%i==0)
      |   ^~

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