foo.cc:10:23: warning: multi-character character constant [-Wmultichar]
   10 |         if(x<0) cout<<'0;'
      |                       ^~~~
foo.cc: In function 'int main()':
foo.cc:10:27: error: expected ';' before 'return'
   10 |         if(x<0) cout<<'0;'
      |                           ^
      |                           ;
   11 |         return 0;
      |         ~~~~~~             

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