inp = open("input.txt", "rb")

n, k = [int(x) for x in inp.readline().split()]

a = []

for i in range(n):
    s = inp.readline() + b' '
    t = ""
    for j in s:
        if (j == ord('-')) and (len(t) == 0):
            t += chr(j)
        elif (j >= ord('0')) and (j <= ord('9')):
            t += chr(j)
    a.append(int(t))

a.sort()

#print(a)

open("output.txt", "w").write(str(sum(a[:k])))