/in/foo.cc: In function 'int main()':
/in/foo.cc:33:16: warning: 'a' is used uninitialized in this function [-Wuninitialized]
  int a,b,c,p=(a+b+c)/2;
               ~^~
/in/foo.cc:33:16: warning: 'b' is used uninitialized in this function [-Wuninitialized]
/in/foo.cc:33:18: warning: 'c' is used uninitialized in this function [-Wuninitialized]
  int a,b,c,p=(a+b+c)/2;
              ~~~~^~~