/in/foo.cc: In function 'int main()':
/in/foo.cc:8:7: warning: 'b' is used uninitialized in this function [-Wuninitialized]
  n=c+b*10+a*100;
      ~^~~
/in/foo.cc:8:5: warning: 'c' is used uninitialized in this function [-Wuninitialized]
  n=c+b*10+a*100;
    ~^~~~~
/in/foo.cc:8:12: warning: 'a' is used uninitialized in this function [-Wuninitialized]
  n=c+b*10+a*100;
           ~^~~~