foo.cc: In function 'int main()':
foo.cc:4:13: warning: unused variable 'd' [-Wunused-variable]
    4 |  double a,b,d,e;
      |             ^
foo.cc:4:15: warning: unused variable 'e' [-Wunused-variable]
    4 |  double a,b,d,e;
      |               ^
foo.cc:6:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    6 |  scanf("%lf,%lf,%c",&a,&b,&c);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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