#include <cstdio>
#include <cstring>

int sum[1005][1005], real[1005][1005], buc[1005], n = 1000, m = 500;
bool vis[1005][1005];
inline bool ask(int l, int r) {
	if (!vis[l][r]) {
		printf("? %d %d\n", l, r);
		fflush(stdout);
		scanf("%d", &sum[l][r]);
		vis[l][r] = true;
	}
	return sum[l][r];
}

int main() {
	for (int len = m - 1; len <= m; ++ len) {
		for (int i = 1; i + len - 1 <= n; ++ i) {
			memset(buc, 0, sizeof buc);
			int j = i + len - 1;
			for (int k = i; k < j && k <= i + 170; ++ k) {
				ask(i, k), ask(k + 1, j);
				if (sum[i][k] + sum[k + 1][j] <= j - i + 1) ++ buc[sum[i][k] + sum[k + 1][j]];
			}
			int major = 0;
			for (int k = 1; k <= j - i + 1; ++ k) if (buc[k] > buc[major]) major = k;
			real[i][j] = major;
		}
	}
	for (int i = 1; i <= n; ++ i) {
		if (i <= n - m + 1) printf("%d", real[i][i + m] - real[i][i + m - 2]);
		else printf("%d", real[i - m + 1][i] - real[i - m + 2][i]);
	}
	return 0;
}