#include <bits/stdc++.h>
using namespace std;
template <typename T>
void read(T& a) {
  cin >> a;
}
template <typename T>
void read(T& a, T& b) {
  cin >> a >> b;
}
template <typename T>
void read(T& a, T& b, T& c) {
  cin >> a >> b >> c;
}
void solve() {}
int n, m, myX, myY;
void print(int i, int j) {
  cout << (i + myX - 2) % n + 1 << " " << (j + myY - 2) % m + 1 << "\n";
}
int main() {
  read(n, m, myX);
  read(myY);
  for (int i = 1; i <= n; ++i) {
    if (i & 1)
      for (int j = 1; j <= m; ++j) print(i, j);
    else
      for (int j = m; j >= 1; --j) print(i, j);
  }
  return 0;
}
