#include <bits/stdc++.h>

using namespace std;

int n, m, C;

int dp[10][10], was[10][10];
int cnt[10][10], r[10];


int go (int cars, int routes) {
    if (was[cars][routes]) return dp[cars][routes];
    if (cars < routes || (cars != 0 && !routes)) return -1;

    was[cars][routes] = 1;
    dp[cars][routes] = -1;
    for (int cur = 1; cur <= cars - routes + 1; cur++) {
        int last = dp[cars - cur][routes - 1];
        if (last != -1) {
            dp[cars][routes] = max (dp[cars][routes], last + cnt[routes][cur] * C - r[routes] * cur);
        }
    }
    return dp[cars][routes];
}

int main() {

    cin >> n >> m >> C;
    for (int i = 1; i <= n; i++) cin >> r[i];

    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            cin >> cnt[i][j];

    was[0][0] = 1;
    cout << go (m, n) << endl;
}

/*
3 5
30
3000 2500 2000

300 500 600 600
300 600 700 700
300 450 500 500
*/