#include<stdio.h>
int abs(int n)
{
	if (n < 0)
		return -n;
	else
		return n;
}
int d(int x1, int y1, int x2, int y2)
{
	return abs(x1 - x2) + abs(y1 - y2);
}
int main()
{
	int t, sx, sy, gx, gy;
	scanf("%d %d %d %d %d", &t, &sx, &sy, &gx, &gy);
	int min, mid, max;
	int x, y;
	min = 0;
	max = t;
	while (max - min > 1)
	{
		mid = (max + min) / 2;
		printf("? %d\n", mid);
		fflush(stdout);
		scanf("%d %d", &x, &y);
		if (d(sx, sy, x, y) > d(x, y, gx, gy))
			max = mid;
		else
			min = mid;
	}
	printf("! %d\n", min);
	return 0;
}