#include <bits/stdc++.h>
using namespace std;
const long long MOD = (1 ? 100000000000000007 : 233333333333333333);
const int mod = (1 ? 1000000007 : 998244353);
const long long INF = 0x7fffffffffffffff;
const int inf = 0x7fffffff;
const double eps = 1e-9;
const int N = 4e5 + 5;
clock_t start, finish;
void time_in() { start = clock(); }
void time_out() {
  finish = clock();
  double tim = (double)(finish - start) / CLOCKS_PER_SEC;
  printf("Running time is %lf\n", tim);
}
inline long long mul(long long a, long long b) {
  long long s = 0;
  while (b) {
    if (b & 1) s = (s + a) % mod;
    a = (a << 1) % mod;
    b >>= 1;
  }
  return s % mod;
}
inline long long pow_mul(long long a, long long b) {
  long long s = 1;
  while (b) {
    if (b & 1) s = mul(s, a);
    a = mul(a, a);
    b >>= 1;
  }
  return s;
}
inline long long poww(long long a, long long b) {
  long long s = 1;
  while (b) {
    if (b & 1) s = (s * a) % mod;
    a = (a * a) % mod;
    b >>= 1;
  }
  return s % mod;
}
inline int read() {
  char c = getchar();
  int sgn = 1, ret = 0;
  while (c != '-' && (c < '0' || c > '9')) c = getchar();
  if (c == '-') sgn = -1, c = getchar();
  while (c >= '0' && c <= '9') ret = ret * 10 + c - 48, c = getchar();
  return ret * sgn;
}
void write(int x) {
  if (x > 9) write(x / 10);
  putchar(x % 10 + '0');
}
inline long long phi(long long x) {
  long long ans = x;
  for (long long i = 2; i * i <= x; i++)
    if (x % i == 0) {
      ans -= ans / i;
      while (x % i == 0) x /= i;
    }
  if (x > 1) ans -= ans / x;
  return ans;
}
int st[5][3] = {-1, 0, 0, 1, 0, 0, 0, -1, 0, 0, 1, 0, 0, 0, 1};
int t, cas;
int m, n;
long long dp[105][105][105];
int c[105];
long long a[105][105];
int main() {
  int k;
  while (~scanf("%d%d%d", &n, &m, &k)) {
    for (int i = 1; i <= n; i++) scanf("%d", &c[i]);
    for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= m; j++) {
        scanf("%lld", &a[i][j]);
      }
    }
    memset(dp, 1, sizeof dp);
    if (c[1])
      dp[1][1][c[1]] = 0;
    else {
      for (int i = 1; i <= m; i++) dp[1][1][i] = a[1][i];
    }
    for (int i = 2; i <= n; i++) {
      if (c[i] == 0) {
        for (int j = 1; j <= k && j <= i; j++) {
          for (int v = 1; v <= m; v++) {
            dp[i][j][v] = dp[i - 1][j][v] + a[i][v];
            for (int x = 1; x <= m; x++) {
              if (x != v)
                dp[i][j][v] = min(dp[i][j][v], dp[i - 1][j - 1][x] + a[i][v]);
            }
          }
        }
      } else {
        int v = c[i];
        for (int j = 1; j <= k && j <= i; j++) {
          dp[i][j][v] = dp[i - 1][j][v];
          for (int x = 1; x <= m; x++) {
            if (x != v) dp[i][j][v] = min(dp[i][j][v], dp[i - 1][j - 1][x]);
          }
        }
      }
    }
    long long ans = INF;
    for (int i = 1; i <= m; i++) ans = min(ans, dp[n][k][i]);
    if (ans < 72340172838076673)
      printf("%lld\n", ans);
    else
      printf("-1\n");
  }
}
