import java.util.Scanner;

public class NickyEnMarkEndTooLargeBruteForce {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		int n = scanner.nextInt();
		int lx = 0;
		int hx = n;
		int ly = 0;
		int hy = n;
		int globalmaxx = 0;
		int globalmaxy = 0;
		int globalmaxh = 0;

		while (n > 30) {
			int maxh = 0;
			int quarter = n / 4;
			int half = n / 2;
			int maxline = -1;
			int[] search = new int[]{ly + quarter, ly + half, ly + 3 * quarter};
			for (int x = lx; x < hx; x++) {
				for (int i = 0; i < 3; i++) {
					System.out.println("? " + (x + 1) + " " + (search[i] + 1));
					System.out.flush();
					int h = scanner.nextInt();
					if (h > maxh) {
						maxh = h;
						maxline = i;
					}

					if (h > globalmaxh) {
						globalmaxh = h;
						globalmaxx = x;
						globalmaxy = search[i];
					}
				}
			}

			if (maxh < globalmaxh) {
				maxline = -1;
				for (int i = 0; i < 3; i++) {
					if (globalmaxy < search[i]) {
						maxline = i;
						break;
					}
				}
				if (maxline == -1) {
					maxline = 2;
				}
			}

			if (maxline == 0) {
				hy = ly + half;
			} else if (maxline == 2) {
				ly = hy - half;
			} else {
				ly = ly + quarter;
				hy = ly + half;
			}

			maxh = 0;
			search = new int[]{lx + quarter, lx + half, lx + 3 * quarter};
			for (int y = ly; y < hy; y++) {
				for (int i = 0; i < 3; i++) {
					System.out.println("? " + (search[i] + 1) + " " + (y + 1));
					System.out.flush();
					int h = scanner.nextInt();
					if (h > maxh) {
						maxh = h;
						maxline = i;
					}

					if (h > globalmaxh) {
						globalmaxh = h;
						globalmaxx = search[i];
						globalmaxy = y;
					}
				}
			}

			if (maxh < globalmaxh) {
				maxline = -1;
				for (int i = 0; i < 3; i++) {
					if (globalmaxx < search[i]) {
						maxline = i;
						break;
					}
				}
				if (maxline == -1) {
					maxline = 2;
				}
			}

			if (maxline == 0) {
				hx = lx + half;
			} else if (maxline == 2) {
				lx = hx - half;
			} else {
				lx = lx + quarter;
				hx = lx + half;
			}

			n /= 2;
		}

		int maxh = 0;
		for (int x = lx; x < hx; x++) {
			for (int y = ly; y < hy; y++) {
				System.out.println("? " + (x + 1) + " " + (y + 1));
				System.out.flush();
				int h = scanner.nextInt();
				if (h > maxh) {
					maxh = h;
				}
			}
		}

		System.out.println("! " + maxh);
		System.out.flush();
	}
}