#include <bits/stdc++.h>
using namespace std;
int main() {
  long long b, r, g, w, i, j = 0, p = 0, n, m, s1, s2;
  cin >> n >> m >> s1 >> s2;
  if (s2 == 2) {
    cout << s1 << " " << s2 << endl;
    cout << "1"
         << " " << s2 << endl;
    for (i = 1; i <= n; i++) {
      if (i % 2 == 1) {
        for (j = 1; j <= m; j++) {
          if ((i == 1 && j == 2) || (i == s1 && j == 2)) {
            continue;
          } else
            cout << i << " " << j << endl;
        }
      } else {
        for (j = m; j >= 1; j--) {
          if ((i == 1 && j == 2) || (i == s1 && j == 2)) {
            continue;
          } else
            cout << i << " " << j << endl;
        }
      }
    }
  } else {
    cout << s1 << " " << s2 << endl;
    cout << s1 << " "
         << "2" << endl;
    cout << "1"
         << " "
         << "2" << endl;
    for (i = 1; i <= n; i++) {
      if (i % 2 == 1) {
        for (j = 1; j <= m; j++) {
          if ((i == 1 && j == 2) || (i == s1 && j == s2) ||
              (i == s1 && j == 2)) {
            continue;
          } else
            cout << i << " " << j << endl;
        }
      } else {
        for (j = m; j >= 1; j--) {
          if ((i == 1 && j == 2) || (i == s1 && j == s2) ||
              (i == s1 && j == 2)) {
            continue;
          } else
            cout << i << " " << j << endl;
        }
      }
    }
  }
  return 0;
}
