Once Bob got to a sale of old TV sets. There were n TV sets at that sale. TV set with index i costs ai bellars. Some TV sets have a negative price — their owners are ready to pay Bob if he buys their useless apparatus. Bob can «buy» any TV sets he wants. Though he's very strong, Bob can carry at most m TV sets, and he has no desire to go to the sale for the second time. Please, help Bob find out the maximum sum of money that he can earn.

Input

The first line contains two space-separated integers n and m (1 ≤ m ≤ n ≤ 100) — amount of TV sets at the sale, and amount of TV sets that Bob can carry. The following line contains n space-separated integers ai ( - 1000 ≤ ai ≤ 1000) — prices of the TV sets. 

Output

Output the only number — the maximum sum of money that Bob can earn, given that he can carry at most m TV sets.

Examples

Input

5 3
-6 0 35 -2 4


Output

8


Input

4 2
7 0 0 -7


Output

7
# https://codeforces.com/problemset/problem/34/B

"""
n objects with the ith object costing a_i
Some objects have negative price

Can take at most m (m<=n) objects
Find the max sum of money Bob can earn

# So find the negatives and take that into an array
# Then sort that array
# Then take the m largest
"""

import sys

n, m = map(int, sys.stdin.readline().split())
a = list(map(int, sys.stdin.readline().split()))

negatives = []

for price in a:
    if price <= 0:
        negatives.append(price)

negatives = sorted(negatives)

if len(negatives) <= m:
    answer = - sum(negatives)
else:
    answer = - sum(negatives[:m])

sys.stdout.write(str(answer))

