DLee came to a new level. What is waiting for him is a tall building with $n$ floors, with a monster on each stair, the $i$-th of which has health point $a_i$.
DLee starts from the ground(which can be regarded as the 0-th floor), with a base attacking point $a_0$. He can choose to jump $1,2,\dots,k$ floors up or walk $1$ floor down, but he cannot go to floors whose monster has a health point strictly greater than his attacking point, nor can he go to floors which had been visited. Once he comes and defeats a monster he can absorb his health point and add it to his attacking point.
Note that DLee should always be on floors $\{0,1,2,3,\dots,n\}$.
Now DLee asks you whether it is possible to defeat all the monsters and pass the level.