/in/foo.cc: In function 'int main()':
/in/foo.cc:11:3: error: 'j' was not declared in this scope
   j-=1;
   ^
/in/foo.cc:6:8: warning: unused variable 'b' [-Wunused-variable]
  int a,b,c;
        ^
/in/foo.cc:6:10: warning: unused variable 'c' [-Wunused-variable]
  int a,b,c;
          ^