시간 제한메모리 제한제출정답맞힌 사람정답 비율
1 초 256 MB49615813334.545%

문제

정수 수열 a1, a2, ..., an이 있을 때, 1 ≤ i ≤ n − k + 1 인 모든 정수 i에 대해서, ai + ai+1 + ... + ai+k−1 이 짝수라면, 이 수열을 k-짝합 수열이라고 정의한다.

당신은 수열에 있는 몇 개의 원소를 원하는 정수로 바꿀 수 있다. 최소 몇 개의 원소를 바꿔야지 수열을 k-짝합 수열로 만들 수 있는가?

입력

첫 번째 줄에는 정수 n, k가 주어진다. (1 ≤ k ≤ n ≤ 106)

두 번째 줄에는 n개의 정수가 주어진다. 이 중 i 번째 정수는 ai(0 ≤ ai ≤ 109) 를 뜻한다.

출력

바꿔야 하는 원소의 최소 개수를 출력한다.

예제 입력 1

8 3
1 2 3 4 5 6 7 8

예제 출력 1

3
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