#include <bits/stdc++.h>
using namespace std;
void readi(int &x) {
  int v = 0, f = 1;
  char c = getchar();
  while (!isdigit(c) && c != '-') c = getchar();
  if (c == '-')
    f = -1;
  else
    v = v * 10 + c - '0';
  while (isdigit(c = getchar())) v = v * 10 + c - '0';
  x = v * f;
}
void readll(long long &x) {
  long long v = 0ll, f = 1ll;
  char c = getchar();
  while (!isdigit(c) && c != '-') c = getchar();
  if (c == '-')
    f = -1;
  else
    v = v * 10 + c - '0';
  while (isdigit(c = getchar())) v = v * 10 + c - '0';
  x = v * f;
}
void readc(char &x) {
  char c;
  while ((c = getchar()) == ' ')
    ;
  x = c;
}
void writes(string s) { puts(s.c_str()); }
void writeln() { writes(""); }
void writei(int x) {
  if (!x) putchar('0');
  char a[25];
  int top = 0;
  while (x) {
    a[++top] = (x % 10) + '0';
    x /= 10;
  }
  while (top) {
    putchar(a[top]);
    top--;
  }
}
void writell(long long x) {
  if (!x) putchar('0');
  char a[25];
  int top = 0;
  while (x) {
    a[++top] = (x % 10) + '0';
    x /= 10;
  }
  while (top) {
    putchar(a[top]);
    top--;
  }
}
long long n, m, aa, b, i, j, k, mx[1005][1005], mx2[1005][1005], a[1005][1005],
    l, r, qx[1005][2], vis[1005][1005], c[1005][1005];
vector<pair<long long, pair<int, int> > > s;
vector<pair<pair<int, int>, long long> > ans;
int main() {
  ios::sync_with_stdio(false);
  ;
  cin >> n >> m >> aa >> b;
  for (i = 1; i <= n; i++) {
    for (j = 1; j <= m; j++) {
      cin >> a[i][j];
      c[i][j] = c[i - 1][j] + c[i][j - 1] - c[i - 1][j - 1] + a[i][j];
    }
  }
  for (i = 1; i <= n; i++) {
    k = 1;
    l = r = 0;
    for (j = 1; j <= m; j++) {
      while (k <= m && j + b > k) {
        while (l < r && qx[r - 1][0] >= a[i][k]) r--;
        qx[r][0] = a[i][k];
        qx[r][1] = k;
        r++;
        k++;
      }
      while (l < r && qx[l][1] < j) l++;
      mx[i][j] = qx[l][0];
    }
  }
  for (i = 1; i <= m; i++) {
    k = 1;
    l = r = 0;
    for (j = 1; j <= n; j++) {
      while (k <= n && j + aa > k) {
        while (l < r && qx[r - 1][0] >= mx[k][i]) r--;
        qx[r][0] = mx[k][i];
        qx[r][1] = k;
        r++;
        k++;
      }
      while (l < r && qx[l][1] < j) l++;
      mx2[j][i] = qx[l][0];
    }
  }
  for (i = 1; i + aa - 1 <= n; i++) {
    for (j = 1; j + b - 1 <= m; j++) {
      s.push_back(make_pair(c[i + aa - 1][j + b - 1] - c[i + aa - 1][j - 1] -
                                c[i - 1][j + b - 1] + c[i - 1][j - 1] -
                                mx2[i][j] * aa * b,
                            make_pair(i, j)));
    }
  }
  stable_sort((s).begin(), (s).end());
  int pos = 0;
  while (pos < s.size()) {
    pair<long long, pair<int, int> > cur = s[pos];
    pos++;
    i = cur.second.first, j = cur.second.second;
    if (vis[i][j]) continue;
    for (int xx = max(i - aa + 1, 1ll); xx <= i + aa - 1 && xx <= n; xx++) {
      for (int yy = max(j - b + 1, 1ll); yy <= j + b - 1 && yy <= m; yy++) {
        vis[xx][yy] = 1;
      }
    }
    ans.push_back(make_pair(make_pair(i, j), cur.first));
  }
  writell((long long)ans.size());
  writeln();
  for (i = 0; i < ans.size(); i++)
    printf("%d %d %I64d\n", ans[i].first.first, ans[i].first.second,
           ans[i].second);
  return 0;
}
