#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<vector<int>> DP(K + 1, vector<int>(N, 0));

    DP[0][0] = A[0] + C[0];
    DP[1][0] = A[0] + B[0];

    for (int i = 1; i < N; i++) {
        DP[0][i] = DP[0][i - 1] + A[i] + C[i];
    }

    for (int k = 1; k <= K; k++) {
        for (int n = 1; n < N; n++) {
            int tare = (DP[k][n - 1] != 0) ? DP[k][n - 1] + A[n] + C[n] : 0;
            int sio = (DP[k - 1][n - 1] != 0) ? DP[k - 1][n - 1] + A[n] + B[n] : 0;
            DP[k][n] = max(tare, sio);
        }
    }

    cout << DP[K][N - 1] << endl;

    return 0;
}