/in/foo.cc: In function 'int main()':
/in/foo.cc:5:10: warning: unused variable 'b' [-Wunused-variable]
  int a=0,b,c; 
          ^
/in/foo.cc:5:12: warning: unused variable 'c' [-Wunused-variable]
  int a=0,b,c; 
            ^