foo.cc: In function 'int main()':
foo.cc:9:2: error: expected ',' or ';' before 'while'
    9 |  while(n)
      |  ^~~~~
foo.cc:6:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    6 |  scanf("%d",&n);
      |  ~~~~~^~~~~~~~~

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