Problem: Boboniu likes playing chess with his employees. As we know, no employee can beat the boss in the chess game, so Boboniu has never lost in any round.

You are a new applicant for his company. Boboniu will test you with the following chess question:

Consider a n× m grid (rows are numbered from 1 to n, and columns are numbered from 1 to m). You have a chess piece, and it stands at some cell (S_x,S_y) which is not on the border (i.e. 2 ≤ S_x ≤ n-1 and 2 ≤ S_y ≤ m-1).

From the cell (x,y), you can move your chess piece to (x,y') (1≤ y'≤ m, y' ≠ y) or (x',y) (1≤ x'≤ n, x'≠ x). In other words, the chess piece moves as a rook. From the cell, you can move to any cell on the same row or column.

Your goal is to visit each cell exactly once. Can you find a solution?

Note that cells on the path between two adjacent cells in your route are not counted as visited, and it is not required to return to the starting point.

Input

The only line of the input contains four integers n, m, S_x and S_y (3≤ n,m≤ 100, 2 ≤ S_x ≤ n-1, 2 ≤ S_y ≤ m-1) — the number of rows, the number of columns, and the initial position of your chess piece, respectively.

Output

You should print n⋅ m lines.

The i-th line should contain two integers x_i and y_i (1 ≤ x_i ≤ n, 1 ≤ y_i ≤ m), denoting the i-th cell that you visited. You should print exactly nm pairs (x_i, y_i), they should cover all possible pairs (x_i, y_i), such that 1 ≤ x_i ≤ n, 1 ≤ y_i ≤ m.

We can show that under these constraints there always exists a solution. If there are multiple answers, print any.

Examples

Input


3 3 2 2


Output


2 2
1 2
1 3
2 3
3 3
3 2
3 1
2 1
1 1


Input


3 4 2 2


Output


2 2
2 1
2 3
2 4
1 4
3 4
3 3
3 2
3 1
1 1
1 2
1 3

Note

Possible routes for two examples:

<image>

Solution (in PYTHON3):

Solution:
# ---------------------------iye ha aam zindegi---------------------------------------------
import math
import heapq, bisect
import sys
from collections import deque, defaultdict
from fractions import Fraction
import sys
mod = 10 ** 9 + 7
mod1 = 998244353
#setrecursionlimit(300000)
# ------------------------------warmup----------------------------
import os
import sys
from io import BytesIO, IOBase
BUFSIZE = 8192
sys.setrecursionlimit(300000)
class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip("\r\n")


# -------------------game starts now----------------------------------------------------import math
class TreeNode:
    def __init__(self, k, v):
        self.key = k
        self.value = v
        self.left = None
        self.right = None
        self.parent = None
        self.height = 1
        self.num_left = 1
        self.num_total = 1


class AvlTree:

    def __init__(self):
        self._tree = None

    def add(self, k, v):
        if not self._tree:
            self._tree = TreeNode(k, v)
            return
        node = self._add(k, v)
        if node:
            self._rebalance(node)

    def _add(self, k, v):
        node = self._tree
        while node:
            if k < node.key:
                if node.left:
                    node = node.left
                else:
                    node.left = TreeNode(k, v)
                    node.left.parent = node
                    return node.left
            elif node.key < k:
                if node.right:
                    node = node.right
                else:
                    node.right = TreeNode(k, v)
                    node.right.parent = node
                    return node.right
            else:
                node.value = v
                return

    @staticmethod
    def get_height(x):
        return x.height if x else 0

    @staticmethod
    def get_num_total(x):
        return x.num_total if x else 0

    def _rebalance(self, node):

        n = node
        while n:
            lh = self.get_height(n.left)
            rh = self.get_height(n.right)
            n.height = max(lh, rh) + 1
            balance_factor = lh - rh
            n.num_total = 1 + self.get_num_total(n.left) + self.get_num_total(n.right)
            n.num_left = 1 + self.get_num_total(n.left)

            if balance_factor > 1:
                if self.get_height(n.left.left) < self.get_height(n.left.right):
                    self._rotate_left(n.left)
                self._rotate_right(n)
            elif balance_factor < -1:
                if self.get_height(n.right.right) < self.get_height(n.right.left):
                    self._rotate_right(n.right)
                self._rotate_left(n)
            else:
                n = n.parent

    def _remove_one(self, node):
        """
        Side effect!!! Changes node. Node should have exactly one child
        """
        replacement = node.left or node.right
        if node.parent:
            if AvlTree._is_left(node):
                node.parent.left = replacement
            else:
                node.parent.right = replacement
            replacement.parent = node.parent
            node.parent = None
        else:
            self._tree = replacement
            replacement.parent = None
        node.left = None
        node.right = None
        node.parent = None
        self._rebalance(replacement)

    def _remove_leaf(self, node):
        if node.parent:
            if AvlTree._is_left(node):
                node.parent.left = None
            else:
                node.parent.right = None
            self._rebalance(node.parent)
        else:
            self._tree = None
        node.parent = None
        node.left = None
        node.right = None

    def remove(self, k):
        node = self._get_node(k)
        if not node:
            return
        if AvlTree._is_leaf(node):
            self._remove_leaf(node)
            return
        if node.left and node.right:
            nxt = AvlTree._get_next(node)
            node.key = nxt.key
            node.value = nxt.value
            if self._is_leaf(nxt):
                self._remove_leaf(nxt)
            else:
                self._remove_one(nxt)
            self._rebalance(node)
        else:
            self._remove_one(node)

    def get(self, k):
        node = self._get_node(k)
        return node.value if node else -1

    def _get_node(self, k):
        if not self._tree:
            return None
        node = self._tree
        while node:
            if k < node.key:
                node = node.left
            elif node.key < k:
                node = node.right
            else:
                return node
        return None

    def get_at(self, pos):
        x = pos + 1
        node = self._tree
        while node:
            if x < node.num_left:
                node = node.left
            elif node.num_left < x:
                x -= node.num_left
                node = node.right
            else:
                return (node.key, node.value)
        raise IndexError("Out of ranges")

    @staticmethod
    def _is_left(node):
        return node.parent.left and node.parent.left == node

    @staticmethod
    def _is_leaf(node):
        return node.left is None and node.right is None

    def _rotate_right(self, node):
        if not node.parent:
            self._tree = node.left
            node.left.parent = None
        elif AvlTree._is_left(node):
            node.parent.left = node.left
            node.left.parent = node.parent
        else:
            node.parent.right = node.left
            node.left.parent = node.parent
        bk = node.left.right
        node.left.right = node
        node.parent = node.left
        node.left = bk
        if bk:
            bk.parent = node
        node.height = max(self.get_height(node.left), self.get_height(node.right)) + 1
        node.num_total = 1 + self.get_num_total(node.left) + self.get_num_total(node.right)
        node.num_left = 1 + self.get_num_total(node.left)

    def _rotate_left(self, node):
        if not node.parent:
            self._tree = node.right
            node.right.parent = None
        elif AvlTree._is_left(node):
            node.parent.left = node.right
            node.right.parent = node.parent
        else:
            node.parent.right = node.right
            node.right.parent = node.parent
        bk = node.right.left
        node.right.left = node
        node.parent = node.right
        node.right = bk
        if bk:
            bk.parent = node
        node.height = max(self.get_height(node.left), self.get_height(node.right)) + 1
        node.num_total = 1 + self.get_num_total(node.left) + self.get_num_total(node.right)
        node.num_left = 1 + self.get_num_total(node.left)

    @staticmethod
    def _get_next(node):
        if not node.right:
            return node.parent
        n = node.right
        while n.left:
            n = n.left
        return n


# -----------------------------------------------binary seacrh tree---------------------------------------
class SegmentTree1:
    def __init__(self, data, default=0, func=lambda a, b: max(a, b)):
        """initialize the segment tree with data"""
        self._default = default
        self._func = func
        self._len = len(data)
        self._size = _size = 1 << (self._len - 1).bit_length()

        self.data = [default] * (2 * _size)
        self.data[_size:_size + self._len] = data
        for i in reversed(range(_size)):
            self.data[i] = func(self.data[i + i], self.data[i + i + 1])

    def __delitem__(self, idx):
        self[idx] = self._default

    def __getitem__(self, idx):
        return self.data[idx + self._size]

    def __setitem__(self, idx, value):
        idx += self._size
        self.data[idx] = value
        idx >>= 1
        while idx:
            self.data[idx] = self._func(self.data[2 * idx], self.data[2 * idx + 1])
            idx >>= 1

    def __len__(self):
        return self._len

    def query(self, start, stop):
        if start == stop:
            return self.__getitem__(start)
        stop += 1
        start += self._size
        stop += self._size

        res = self._default
        while start < stop:
            if start & 1:
                res = self._func(res, self.data[start])
                start += 1
            if stop & 1:
                stop -= 1
                res = self._func(res, self.data[stop])
            start >>= 1
            stop >>= 1
        return res

    def __repr__(self):
        return "SegmentTree({0})".format(self.data)


# -------------------game starts now----------------------------------------------------import math
class SegmentTree:
    def __init__(self, data, default=0, func=lambda a, b: a + b):
        """initialize the segment tree with data"""
        self._default = default
        self._func = func
        self._len = len(data)
        self._size = _size = 1 << (self._len - 1).bit_length()

        self.data = [default] * (2 * _size)
        self.data[_size:_size + self._len] = data
        for i in reversed(range(_size)):
            self.data[i] = func(self.data[i + i], self.data[i + i + 1])

    def __delitem__(self, idx):
        self[idx] = self._default

    def __getitem__(self, idx):
        return self.data[idx + self._size]

    def __setitem__(self, idx, value):
        idx += self._size
        self.data[idx] = value
        idx >>= 1
        while idx:
            self.data[idx] = self._func(self.data[2 * idx], self.data[2 * idx + 1])
            idx >>= 1

    def __len__(self):
        return self._len

    def query(self, start, stop):
        if start == stop:
            return self.__getitem__(start)
        stop += 1
        start += self._size
        stop += self._size

        res = self._default
        while start < stop:
            if start & 1:
                res = self._func(res, self.data[start])
                start += 1
            if stop & 1:
                stop -= 1
                res = self._func(res, self.data[stop])
            start >>= 1
            stop >>= 1
        return res

    def __repr__(self):
        return "SegmentTree({0})".format(self.data)


# -------------------------------iye ha chutiya zindegi-------------------------------------
class Factorial:
    def __init__(self, MOD):
        self.MOD = MOD
        self.factorials = [1, 1]
        self.invModulos = [0, 1]
        self.invFactorial_ = [1, 1]

    def calc(self, n):
        if n <= -1:
            print("Invalid argument to calculate n!")
            print("n must be non-negative value. But the argument was " + str(n))
            exit()
        if n < len(self.factorials):
            return self.factorials[n]
        nextArr = [0] * (n + 1 - len(self.factorials))
        initialI = len(self.factorials)
        prev = self.factorials[-1]
        m = self.MOD
        for i in range(initialI, n + 1):
            prev = nextArr[i - initialI] = prev * i % m
        self.factorials += nextArr
        return self.factorials[n]

    def inv(self, n):
        if n <= -1:
            print("Invalid argument to calculate n^(-1)")
            print("n must be non-negative value. But the argument was " + str(n))
            exit()
        p = self.MOD
        pi = n % p
        if pi < len(self.invModulos):
            return self.invModulos[pi]
        nextArr = [0] * (n + 1 - len(self.invModulos))
        initialI = len(self.invModulos)
        for i in range(initialI, min(p, n + 1)):
            next = -self.invModulos[p % i] * (p // i) % p
            self.invModulos.append(next)
        return self.invModulos[pi]

    def invFactorial(self, n):
        if n <= -1:
            print("Invalid argument to calculate (n^(-1))!")
            print("n must be non-negative value. But the argument was " + str(n))
            exit()
        if n < len(self.invFactorial_):
            return self.invFactorial_[n]
        self.inv(n)  # To make sure already calculated n^-1
        nextArr = [0] * (n + 1 - len(self.invFactorial_))
        initialI = len(self.invFactorial_)
        prev = self.invFactorial_[-1]
        p = self.MOD
        for i in range(initialI, n + 1):
            prev = nextArr[i - initialI] = (prev * self.invModulos[i % p]) % p
        self.invFactorial_ += nextArr
        return self.invFactorial_[n]


class Combination:
    def __init__(self, MOD):
        self.MOD = MOD
        self.factorial = Factorial(MOD)

    def ncr(self, n, k):
        if k < 0 or n < k:
            return 0
        k = min(k, n - k)
        f = self.factorial
        return f.calc(n) * f.invFactorial(max(n - k, k)) * f.invFactorial(min(k, n - k)) % self.MOD


# --------------------------------------iye ha combinations ka zindegi---------------------------------
def powm(a, n, m):
    if a == 1 or n == 0:
        return 1
    if n % 2 == 0:
        s = powm(a, n // 2, m)
        return s * s % m
    else:
        return a * powm(a, n - 1, m) % m


# --------------------------------------iye ha power ka zindegi---------------------------------
def sort_list(list1, list2):
    zipped_pairs = zip(list2, list1)

    z = [x for _, x in sorted(zipped_pairs)]

    return z


# --------------------------------------------------product----------------------------------------
def product(l):
    por = 1
    for i in range(len(l)):
        por *= l[i]
    return por


# --------------------------------------------------binary----------------------------------------
def binarySearchCount(arr, n, key):
    left = 0
    right = n - 1

    count = 0

    while (left <= right):
        mid = int((right + left) / 2)

        # Check if middle element is
        # less than or equal to key
        if (arr[mid] < key):
            count = mid + 1
            left = mid + 1

        # If key is smaller, ignore right half
        else:
            right = mid - 1

    return count


# --------------------------------------------------binary----------------------------------------
def countdig(n):
    c = 0
    while (n > 0):
        n //= 10
        c += 1
    return c
def binary(x, length):
    y = bin(x)[2:]
    return y if len(y) >= length else "0" * (length - len(y)) + y

def countGreater(arr, n, k):
    l = 0
    r = n - 1

    # Stores the index of the left most element
    # from the array which is greater than k
    leftGreater = n

    # Finds number of elements greater than k
    while (l <= r):
        m = int(l + (r - l) / 2)
        if (arr[m] >= k):
            leftGreater = m
            r = m - 1

        # If mid element is less than
        # or equal to k update l
        else:
            l = m + 1

    # Return the count of elements
    # greater than k
    return (n - leftGreater)


# --------------------------------------------------binary------------------------------------
for ik in range(1):
    n,m,c,d=map(int,input().split())
    t=0
    cop=c
    while(c!=0):
      if t==0:
          for i in range(d,0,-1):
           print(c,i)
      else:
          for i in range(1,d+1):
              print(c,i)
      c-=1
      t+=1
      t%=2
    t=0
    #print('h')
    c+=1
    while(c!=n+1):
        if t == 0:
            for i in range(d+1,m+1):
                print(c, i)
        else:
            for i in range(m, d,-1):
                print(c, i)
        c+=1
        t+=1
        t%=2
        #print(c)
    t=0
    #print('h')
    c=n
    while(c!=cop):
        if t == 0:
            for i in range(d, 0, -1):
                print(c, i)
        else:
            for i in range(1, d + 1):
                print(c, i)
        c -= 1
        t += 1
        t %= 2