import sys

input = sys.stdin.buffer.readline


class SegmentTree:
    """
    https://qiita.com/dn6049949/items/afa12d5d079f518de368 から拝借しています。
    """

    def __init__(self, size, f=lambda x, y: min(x, y), default=10 ** 6):
        self.size = 2 ** (size - 1).bit_length()
        self.default = default
        self.dat = [default] * (self.size * 2)
        self.f = f

    def initialize(self, A):
        for i, a in enumerate(A, self.size):
            self.dat[i] = a
        for i in range(self.size - 1, 0, -1):
            self.dat[i] = self.f(self.dat[i * 2], self.dat[i * 2 + 1])

    def update(self, i, x):
        i += self.size
        self.dat[i] = x
        while i > 0:
            i >>= 1
            self.dat[i] = self.f(self.dat[i * 2], self.dat[i * 2 + 1])

    def query(self, l, r):
        """半開区間[l,r)"""
        l += self.size
        r += self.size
        lres, rres = self.default, self.default
        while l < r:
            if l & 1:
                lres = self.f(lres, self.dat[l])
                l += 1
            if r & 1:
                r -= 1
                rres = self.f(self.dat[r], rres)
            l >>= 1
            r >>= 1
        res = self.f(lres, rres)
        return res


N, K = map(int, input().split())
A = tuple(map(int, input().split()))
dp = SegmentTree(N + 1)
dp.update(0, 0)
for i, a in enumerate(A, 1):
    dp.update(i, dp.query(max(0, i - K), i) + a)
print(sum(A) - dp.query(N + 1 - K, N + 1))