#include <bits/stdc++.h>
using namespace std;
long long c[105], x[105][105], dp[105][105][105];
int main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long n, m, k, i, j, l, p, ans = 10000000000000000;
  cin >> n >> m >> k;
  for (i = 1; i <= n; i++) cin >> c[i];
  for (i = 1; i <= n; i++)
    for (j = 1; j <= m; j++) cin >> x[i][j];
  for (i = 0; i <= 100; i++)
    for (j = 0; j <= 100; j++)
      for (l = 0; l <= 100; l++) dp[i][j][l] = 10000000000000000;
  if (c[1] == 0) {
    for (i = 1; i <= m; i++) dp[1][1][i] = x[1][i];
  } else
    dp[1][1][c[1]] = 0;
  for (i = 2; i <= n; i++) {
    if (c[i] == 0) {
      for (p = 1; p <= k; p++) {
        for (j = 1; j <= m; j++) {
          for (l = 1; l <= m; l++) {
            if (j == l) {
              dp[i][p][l] = min(dp[i][p][l], dp[i - 1][p][j] + x[i][l]);
            } else {
              dp[i][p + 1][l] = min(dp[i][p + 1][l], dp[i - 1][p][j] + x[i][l]);
            }
          }
        }
      }
    } else {
      for (p = 1; p <= k; p++) {
        for (j = 1; j <= m; j++) {
          if (j == c[i]) {
            dp[i][p][c[i]] = min(dp[i][p][c[i]], dp[i - 1][p][j]);
          } else {
            dp[i][p + 1][c[i]] = min(dp[i][p + 1][c[i]], dp[i - 1][p][j]);
          }
        }
      }
    }
  }
  if (c[n] == 0) {
    for (i = 1; i <= m; i++) ans = min(ans, dp[n][k][i]);
  } else
    ans = dp[n][k][c[n]];
  if (ans != 10000000000000000)
    cout << ans;
  else
    cout << -1;
  return 0;
}
