#include<bits/stdc++.h>
using namespace std;
namespace inter {
	int f[5005] , n , cur;
	mt19937 rnd(1) ;
	void init(int N) {
		n = N ;
		for(int i = 1;i <= n;i++) {
			f[i] = rnd()%2;
		}
		cur = 1;
	}
	int f1() {
		return f[cur] ;
	}
	int left() {
		cur--;
		if(cur == 0) cur = n;
		return f[cur] ;
	}
	int right() {
		cur = cur%n + 1;
		return f[cur];
	}
	int flip() {
		f[cur] ^= 1;
		return f[cur] ;
	}
	void answer(int x) {
		if(x == n) {
			cout << "YES\n" ;
		}
		else {
			cout << "NO\n" ;
			cout << x <<' ' << n << '\n' ;
		}
		exit(0) ;
	}
}
// #define test

const int C1 = 200;
const int C2 = 50;
void run() {

	std::string A;
	std::string B;
	for(int i = 1; i <= C1;i++) {
		int x;
		#ifndef test
		std::cin >> x;
		#endif
		#ifdef test
		if(i == 1) x = inter::f1() ;
		else x = inter::right() ;
		#endif
		B.push_back('0'+x);
		int r = rand() % 2;
		if (r) {
			#ifndef test
			printf("? flip\n");
			fflush(stdout);
			std::cin >> x;
			#endif
			#ifdef test
			x = inter::flip() ;
			#endif
		}
		#ifndef test
		printf("? right\n");
		fflush(stdout);
		#endif
		A.push_back('0'+x);
	}
	for(int i = 3; i <= 50; i++) {
		bool tag = 1;
		for(int j = 0;j < C1 - i * 2; j++) {
			for(int k = 0; k < i; k++) {
				if (A[j + k] != B[j + k + i]) {
					tag = 0;
				}
			}
		}
		if (tag) {
			#ifndef test
			printf("! %d\n",i); fflush(stdout) ;
			exit(0);
			#endif 
			#ifdef test
			inter::answer(i) ;
			#endif
		}
	}
}
void Set() {
	std::string A;
	for(int i = 1; i <= C2; i++) {
		int x;
		int r = rand()%2;
		#ifndef test
		std::cin >> x;
		#endif
		#ifdef test
		x = inter::right() ;
		#endif
		if (r) {
			#ifndef test
			printf("? flip\n");
			fflush(stdout);
			std::cin >> x;
			#endif
			#ifdef test
			x = inter::flip() ;
			#endif
		}
		A.push_back('0' + x);
		#ifndef test
		printf("? right\n");
		fflush(stdout);
		#endif
	}
	std::string str;
	int cnt = 0;
	while(1) {
		int x;
		#ifndef test
		std::cin >> x;
		#endif
		#ifdef test
		x = inter::right() ;
		#endif
		cnt++;
		str.push_back('0' + x);
		if (str.length() >= C2 && str.substr(str.length() - C2, C2) == A) {
			#ifndef test
			printf("! %d\n",cnt);
			fflush(stdout);
			exit(0);
			#endif
			#ifdef test
			inter::answer(cnt) ;
			#endif
		}
		#ifndef test
		printf("? right\n");
		fflush(stdout);
		#endif
	}
}
int main() {
	#ifdef test
	int n;cin >> n;
	inter::init(n) ;
	#endif
	run();
	Set();
}