#include <bits/stdc++.h>
using ll = long long;
using namespace std;
void D() {
  ll n, m, x, y;
  cin >> n >> m >> x >> y;
  map<pair<int, int>, int> mp;
  mp[{x, y}] = 1;
  cout << x << " " << y << " "
       << "\n";
  ;
  if (x != 1) {
    cout << 1 << " " << y << "\n";
    ;
    x = 1;
    mp[{x, y}] = 1;
  }
  if (y != 1) {
    cout << x << " " << 1 << "\n";
    ;
    y = 1;
    mp[{x, y}] = 1;
  }
  bool ok = true;
  for (int i = 1; i <= n; i++) {
    if (ok) {
      for (int j = 1; j <= m; j++) {
        if (!mp[{i, j}]) {
          cout << i << " " << j << "\n";
          ;
          mp[{i, j}] = 1;
        }
      }
    } else {
      for (int j = m; j >= 1; j--) {
        if (!mp[{i, j}]) {
          cout << i << " " << j << "\n";
          ;
          mp[{i, j}] = 1;
        }
      }
    }
    ok ^= true;
  }
}
int main(int argc, char const *argv[]) {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cout.precision(0);
  cout << fixed;
  ll n, m, k, pt(0), ct(0), x, y;
  ll t = 1;
  while (t--) {
    D();
  }
}
