#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    int N, K;
    cin >> N >> K;

    vector<int> A(N);
    vector<int> B(N);
    vector<int> C(N);

    for (int i = 0; i < N; i++) {
        cin >> A[i];
    }

    for (int i = 0; i < N; i++) {
        cin >> B[i];
    }

    for (int i = 0; i < N; i++) {
        cin >> C[i];
    }

    vector<int> TARE(N, 0);
    vector<int> SIO(N, 0);

    TARE[0] = A[0] + C[0];  // 0本目をタレで使用

    for (int i = 1; i < N; i++) {
        TARE[i] = TARE[i - 1] + A[i] + C[i];
    }

    SIO[0] = A[0] + B[0];  // 0本目を塩で使用

    for (int k = 1; k <= K; k++) {
        for (int n = 1; n < N; n++) {
            int n_is_tare = (SIO[n - 1] != 0) ? SIO[n - 1] + A[n] + C[n] : 0;
            int n_is_sio = (TARE[n - 1] != 0) ? TARE[n - 1] + A[n] + B[n] : 0;
            SIO[n] = max(n_is_sio, n_is_tare);
        }

        if (k == K) {
            break;
        } else {
            TARE = SIO;
            fill(SIO.begin(), SIO.end(), 0);
        }
    }

    cout << SIO[N - 1] << endl;

    return 0;
}