#include <bits/stdc++.h>
using namespace std;
long long n, m, sx, sy;
void f(long long i, long long j) {
  cout << (i + sx - 2) % n + 1 << " " << (j + sy - 2) % m + 1 << endl;
}
void solve() {
  cin >> n >> m >> sx >> sy;
  for (long long i = 1; i <= n; i++) {
    if (i & 1) {
      for (long long j = 1; j <= m; j++) {
        f(i, j);
      }
    } else {
      for (long long j = m; j >= 1; j--) {
        f(i, j);
      }
    }
  }
}
signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  solve();
  return 0;
}
