sub f{${"@_"}-->0}<>;$T=<>;$$_=eval"\$T=~y/$_-$_//"for a..zz;$z++while((((f(ha)||f i)&&f(i)||f(j)||f k)&&f(k)||f(tl)||f u)&&f(u)||f(xv)||f"y")&&f("y");print$z