#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
long long quickpow(long long a, long long b) {
  long long res = 1;
  while (b) {
    if (b & 1) res = res * a;
    a = a * a;
    b >>= 1;
  }
  return res;
}
const int N = 1e2 + 5;
int row[N], col[N];
int main(void) {
  int n, m, x, y;
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> m >> x >> y;
  for (int i = 1; i <= n; i++) {
    row[i] = i;
  }
  for (int i = 1; i <= m; i++) {
    col[i] = i;
  }
  swap(col[y], col[m]);
  swap(row[1], row[x]);
  for (int i = 1; i <= n; i++) {
    swap(col[1], col[m]);
    for (int j = 1; j <= m; j++) {
      cout << row[i] << " " << col[j] << endl;
    }
  }
  return 0;
}
