Scube sold you N candles, for each candle i you know its height H[i].
Using a candle during one evening decreases the candle height by 1.
You plan to have at most M romantic evenings. For each evening i you know the number of candles C[i] you want to lit. Find a strategy of lighting the candles in order to maximize the number of evenings you can spend. You are forced to stop after the the night i when you can't light C[i] candles.
Standard input
The first line contains two integers N and M.
The second line contains N integers representing the initial heights of the candles.
The third line contains M integers representing the number of candles you want to lit each evening.
Standard output
Print a single integer representing the maximum number of evening you can spend, satisfying the candle requirements.
Constraints and notes
1≤N,M≤10^5
1<=H[i]<=10^5
1 <=C[i]<=10^5
One way spend 3 romantic evenings would be:
Used candle are written in bold
1 2 5 - before evening 1
1 2 4- after evening 1
1 1 3- after evening 2
0 0 2- after evening 3
Note that you can't satisfy the requirements for evening 4, the answer is 3.
Even though you can satisfy evening 5, you must spend the evenings in order .
