foo.cc: In function 'int main()':
foo.cc:7:11: warning: 'd' is used uninitialized in this function [-Wuninitialized]
  v=3.14*(d/2)*(d/2)*h;
         ~~^~~
foo.cc:7:20: warning: 'h' is used uninitialized in this function [-Wuninitialized]
  v=3.14*(d/2)*(d/2)*h;
    ~~~~~~~~~~~~~~~~^~

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