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
import math
from bisect import bisect_left,bisect,bisect_right
from itertools import accumulate

def index(a, x):
    'Locate the leftmost value exactly equal to x'
    i = bisect_left(a, x)
    if i != len(a) and a[i] == x:
        return i
    raise ValueError

def find_lt(a, x):
    'Find rightmost value less than x'
    i = bisect_left(a, x)
    if i:
        return a[i-1]
    raise ValueError

def find_le(a, x):
    'Find rightmost value less than or equal to x'
    i = bisect_right(a, x)
    if i:
        return a[i-1]
    raise ValueError

def find_gt(a, x):
    'Find leftmost value greater than x'
    i = bisect_right(a, x)
    if i != len(a):
        return a[i]
    raise ValueError

def find_ge(a, x):
    'Find leftmost item greater than or equal to x'
    i = bisect_left(a, x)
    if i != len(a):
        return a[i]
    raise ValueError



st=''

def func(n,m,l):
    l.sort()
    i=0
    s=0
    while i<m and l[i]<0:
       s+=l[i]
       i+=1
    return abs(s)













for _ in range(1):#int(input())):
    n,m=map(int,input().split())
    #n = int(input())
    #inp=input().split()
    #s=input()
    #l1=[]
    l1=list(map(int,input().split()))
    #l1=list(accumulate(list(map(int,input().split()))))
    #q=int(input())
    #l2 = list(map(int, input().split()))
    #l1=input().split()
    #l2=input().split()
    #func(n,m)
    st+=str(int(func(n,m,l1)))+'\n'
print(st)