#ifdef TY
#include "/Users/ty/Desktop/code/ty.h"
#else
#include <bits/stdc++.h>
#endif
using namespace std;
namespace IO
{
  static int Len = 0, _t;
  char out[1 << 25]; // 32MB
  template <typename T>
  inline void read(T &x)
  {
    char ch = getchar();
    x = 0, _t = 0;
    while (ch < '0' || ch > '9')
      _t |= ch == '-', ch = getchar();
    while (ch >= '0' && ch <= '9')
      x = x * 10 + (ch ^ 48), ch = getchar();
    x = _t ? -x : x;
  }
  inline void putc(char ch) { out[Len++] = ch; }
  template <typename T>
  inline void write(T x)
  {
    if (x < 0)
      putc('-'), x = -x;
    if (x > 9)
      write(x / 10);
    out[Len++] = x % 10 + 48;
  }
  inline void flush() { fwrite(out, 1, Len, stdout), Len = 0; }
}
using namespace IO;
#ifdef TY
#define N 10
#else
#define N 1010
#endif
int n, m, k, l, r, q[N], a[N][N], ma[N][N], mi[N][N], Ma[N][N], Mi[N][N], ans = INT_MAX;
int main()
{
#ifdef TY
  freopen("/Users/ty/Desktop/code/data.in", "r", stdin);
  // freopen("my.out", "w", stdout);
#endif
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= m; j++)
      scanf("%d", &a[i][j]);
  // push k to 1 max
  for (int j = 1; j <= m; j++)
  {
    l = 1, r = 0;
    for (int i = 1; i <= n; i++)
    {
      while (l <= r && a[i][j] >= a[q[r]][j])
        r--;
      q[++r] = i;
      while (l <= r && q[l] <= i - k)
        l++;
      ma[i][j] = a[q[l]][j];
    }
  }

  // push k to 1 min
  for (int j = 1; j <= m; j++)
  {
    l = 1, r = 0;
    for (int i = 1; i <= n; i++)
    {
      while (l <= r && a[i][j] <= a[q[r]][j])
        r--;
      q[++r] = i;
      while (l <= r && q[l] <= i - k)
        l++;
      mi[i][j] = a[q[l]][j];
    }
  }

  // cal Smax
  for (int i = 1; i <= n; i++)
  {
    l = 1, r = 0;
    for (int j = 1; j <= m; j++)
    {
      while (l <= r && ma[i][j] >= ma[i][q[r]])
        r--;
      q[++r] = j;
      while (l <= r && q[l] <= j - k)
        l++;
      Ma[i][j] = ma[i][q[l]];
    }
  }

  // cal Smin
  for (int i = 1; i <= n; i++)
  {
    l = 1, r = 0;
    for (int j = 1; j <= m; j++)
    {
      while (l <= r && mi[i][j] <= mi[i][q[r]])
        r--;
      q[++r] = j;
      while (l <= r && q[l] <= j - k)
        l++;
      Mi[i][j] = mi[i][q[l]];
    }
  }

  // cal ans
  for (int i = k; i <= n; i++)
    for (int j = k; j <= m; j++)
      ans = min(ans, Ma[i][j] - Mi[i][j]);

  printf("%d\n", ans);
  return 0;
}