#include <bits/stdc++.h>
using namespace std;
namespace mine {
long long qread() {
  long long ans = 0, f = 1;
  char c = getchar();
  while (c < '0' or c > '9') {
    if (c == '-') f = -1;
    c = getchar();
  }
  while ('0' <= c and c <= '9') ans = ans * 10 + c - '0', c = getchar();
  return ans * f;
}
void write(long long num) {
  if (num < 0) putchar('-'), num = -num;
  if (num >= 10) write(num / 10);
  putchar('0' + num % 10);
}
void write1(long long num) {
  write(num);
  putchar(' ');
}
void write2(long long num) {
  write(num);
  putchar('\n');
}
template <typename T>
inline bool chmax(T &a, const T &b) {
  return a < b ? a = b, 1 : 0;
}
template <typename T>
inline bool chmin(T &a, const T &b) {
  return a > b ? a = b, 1 : 0;
}
long long gcd(long long x, long long y) { return y ? gcd(y, x % y) : x; }
bool IN(long long x, long long l, long long r) { return l <= x and x <= r; }
void gg() {
  puts("No");
  exit(0);
}
const double eps = 1e-8;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
int mm(const int x) { return x >= MOD ? x - MOD : x; }
template <typename T>
void add(T &x, const int &y) {
  x = (x + y >= MOD ? x + y - MOD : x + y);
}
long long qpower(long long x, long long e, int mod = MOD) {
  long long ans = 1;
  while (e) {
    if (e & 1) ans = ans * x % mod;
    x = x * x % mod;
    e >>= 1;
  }
  return ans;
}
long long invm(long long x) { return qpower(x, MOD - 2); }
const int M = 5e6 + 10;
long long fac[M], facinv[M], Inv[M];
long long C(int n, int m) {
  return n < 0 or n < m ? 0 : fac[n] * facinv[m] % MOD * facinv[n - m] % MOD;
}
void PRE() {
  fac[0] = 1;
  for (int i = (1), I = (M - 1); i <= I; i++) fac[i] = fac[i - 1] * i % MOD;
  facinv[M - 1] = invm(fac[M - 1]);
  for (int i = (M - 1), I = (1); i >= I; i--)
    facinv[i - 1] = facinv[i] * i % MOD;
  Inv[1] = 1;
  for (int i = (2), I = (M - 1); i <= I; i++)
    Inv[i] = (MOD - MOD / i) * Inv[MOD % i] % MOD;
}
const int N = 4e4 + 10;
int f[60][N], g[60][N], h[60][N], s[60][N];
int n, m, K;
void work(int i) {
  for (int j = (K), I = (m); j <= I; j++) g[i][j] = max(g[i][j - 1], f[i][j]);
  for (int j = (m), I = (K); j >= I; j--) h[i][j] = max(h[i][j + 1], f[i][j]);
}
void main() {
  n = qread(), m = qread(), K = qread();
  for (int i = (1), I = (n); i <= I; i++)
    for (int j = (1), I = (m); j <= I; j++) s[i][j] = s[i][j - 1] + qread();
  memset(f, -0x3f, sizeof f);
  memset(g, -0x3f, sizeof g);
  memset(h, -0x3f, sizeof h);
  for (int j = (K), I = (m); j <= I; j++)
    f[1][j] = (s[1][j] - s[1][j - K]) + (s[2][j] - s[2][j - K]);
  work(1);
  for (int i = (2), I = (n); i <= I; i++) {
    for (int j = (K), I = (m); j <= I; j++) {
      f[i][j] = max(g[i - 1][j - K], h[i - 1][j + K]);
      for (int j2 = (j - K + 1), I = (j + K - 1); j2 <= I; j2++)
        chmax(f[i][j],
              f[i - 1][j2] - (s[i][min(j2, j)] - s[i][max(j2 - K, j - K)]));
      f[i][j] += (s[i][j] - s[i][j - K]) + (s[i + 1][j] - s[i + 1][j - K]);
    }
    work(i);
  }
  write(g[n][m]);
}
};  // namespace mine
signed main() {
  srand(time(0));
  mine::PRE();
  mine::main();
  if (0)
    cerr << "\n---------------------Zory---------------------\nTime: "
         << 1.0 * clock() / CLOCKS_PER_SEC << "s";
}
