#include <assert.h>
#include <stdio.h>

#define printf(...) /*six feet under's not deep enough*/;

enum { maxsize = 50003, inf = 0x3F3F3F3F };

int horiz_size, vert_size;
int col[maxsize], row[maxsize];
int vert_before[maxsize],
    vert_after[maxsize];
int horiz_before[maxsize],
    horiz_after[maxsize];
int ans;

void calc()
/*
 * Takes O(maxsize) time no matter the input.
 */
{
	int count, cost, i, tmp,
	    best_vert, best_horiz;

	//vert_before
	count = 0;
	cost = 0;
	for(i = 0; i < maxsize - vert_size; i++)
	{
		cost += count; //all previous extended by one
		count += col[i]; //free items on current col

		vert_before[i] = cost;
	}

	//vert_after
	count = 0;
	cost = 0;
	for(i = maxsize - 1; i >= vert_size; i--)
	{
		cost += count;
		count += col[i];

		vert_after[i - vert_size] = cost;
	}

	//vert answer
	best_vert = inf;
	for(i = 0; i < maxsize - vert_size; i++)
	{
		tmp = vert_before[i] + vert_after[i];
		printf("i %d vert before %d after %d sum %d\n",
				i, vert_before[i], vert_after[i], tmp);

		if(tmp < best_vert)
			best_vert = tmp;
	}

	printf("vert_answer %d\n", best_vert);

	
	//horiz_before
	count = 0;
	cost = 0;
	for(i = 0; i < maxsize - horiz_size; i++)
	{
		cost += count;
		count += row[i];

		horiz_before[i] = cost;
	}

	//horiz_after
	count = 0;
	cost = 0;
	for(i = maxsize - 1; i >= horiz_size; i--)
	{
		cost += count;
		count += row[i];

		horiz_after[i - horiz_size] = cost;
	}

	//horiz answer
	best_horiz = inf;
	for(i = 0; i < maxsize - horiz_size; i++)
	{
		tmp = horiz_before[i] + horiz_after[i];
		printf("i %d horiz before %d after %d sum %d\n",
				i, horiz_before[i], horiz_after[i], tmp);

		if(tmp < best_horiz)
			best_horiz = tmp;
	}

	printf("horiz_answer %d\n", best_horiz);

	ans = best_vert + best_horiz;
	printf("sum %d\n", ans);
}

int main()
{
	int count, a, b, i;
	FILE *f = fopen("tribute.in", "r");
	if(!f) return 1;

	fscanf(f, "%d%d%d", &count, &horiz_size, &vert_size);
	for(i = 0; i < count; i++)
	{
		fscanf(f, "%d%d", &a, &b);
		row[a]++;
		col[b]++;
	}

	fclose(f);
	f = fopen("tribute.out", "w");
	if(!f) return 1;

	calc();

	fprintf(f, "%d\n", ans);
	fclose(f);
	return 0;
}