// Matrice bordată și scan line
// Folosește 211 niveluri în stivă (pe world-map.in)
#include <assert.h>
#include <stdio.h>

#define MAX_N 5000
#define MAX_STACK 1000
#define NIL -1

typedef struct {
  int l, c1, c2;
} stack;

char a[MAX_N + 2][MAX_N + 2];
stack s[MAX_STACK];
int ss;
int m, n;
int maxSs;

void push(int l, int c1, int c2) {
  s[ss++] = { l, c1, c2 };
  if (ss > maxSs) {
    maxSs = ss;
  }
}

void pop(int *l, int *c1, int *c2) {
  ss--;
  *l = s[ss].l;
  *c1 = s[ss].c1;
  *c2 = s[ss].c2;
}

void fill(int l, int c) {
  int c1, c2;

  push(l, c, c);
  while (ss) {
    pop(&l, &c1, &c2);
    while (a[l][c1 - 1] == '.') {
      c1--;
    }
    while (a[l][c2 + 1] == '.') {
      c2++;
    }
    for (int i = c1; i <= c2; i++) {
      a[l][i] = 'o';
    }
    for (int nl = l - 1; nl <= l + 1; nl += 2) { // liniile vecine
      int first = NIL;
      for (int i = c1; i <= c2; i++) {
        if (a[nl][i] == '.') {
          if (first == NIL) {
            first = i;
          }
        } else {
          if (first != NIL) {
            push(nl, first, i - 1);
            first = NIL;
          }
        }
      }
      if (first != NIL) {
        push(nl, first, c2);
      }
    }
  }
}

int main(void) {
  int l0, c0;
  FILE *f = fopen("fill.in", "r");
  fscanf(f, "%d %d %d %d\n", &m, &n, &l0, &c0);
  for (int i = 1; i <= m; i++) {
    for (int j = 1; j <= n; j++) {
      a[i][j] = fgetc(f);
    }
    assert(fgetc(f) == '\n');
  }
  fclose(f);

  fill(l0, c0);
  printf("Nivelul maxim: %d\n", maxSs);
  f = fopen("fill.out", "w");
  for (int i = 1; i <= m; i++) {
    for (int j = 1; j <= n; j++) {
      fputc(a[i][j], f);
    }
    fputc('\n', f);
  }
  fclose(f);
}