#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
int main() {
  int n, m, sx, sy;
  cin >> n >> m >> sx >> sy;
  sx--;
  sy--;
  int i, j;
  for (i = 0; i < n; i++) {
    for (j = 0; j < m; j++) {
      cout << sx + 1 << " " << sy + 1 << endl;
      sy++;
      sy %= m;
    }
    sy--;
    sy += m;
    sx++;
    sy %= m;
    sx %= n;
  }
}
