foo.cc: In function 'int main()':
foo.cc:20:15: warning: 'd' may be used uninitialized [-Wmaybe-uninitialized]
   20 |         printf("%.2f",d);
      |         ~~~~~~^~~~~~~~~~
foo.cc:5:19: note: 'd' was declared here
    5 |         float a,b,d;
      |                   ^

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