/in/foo.cc: In function 'int main()':
/in/foo.cc:13:11: error: 'b' was not declared in this scope
     cout<<b<<endl;
           ^
/in/foo.cc:6:13: warning: unused variable 'c' [-Wunused-variable]
     int x=0,c,e,f,y;
             ^
/in/foo.cc:6:15: warning: unused variable 'e' [-Wunused-variable]
     int x=0,c,e,f,y;
               ^
/in/foo.cc:6:17: warning: unused variable 'f' [-Wunused-variable]
     int x=0,c,e,f,y;
                 ^