#include<bits/stdc++.h>
#define int long long
#define double long double
#define lowbit(x) x&(-x)
#define fastios ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define endl '\n'
#define el puts("")
#define udm unordered_map<int,int>
#define set_0(a) memset(&a,0,sizeof(a))
#define set_unint(a) memset(&a,-1,sizeof(a))
using namespace std;
//define_var
const int M=2e5+9,inf=1e18;
bool isok[M];
int n,k1,k2;
int pro;
//define_var
//function_begin
//int read()
//{
//	int x=0,f=1;
//	char c=getchar();
//	while(c<'0'||c>'9'){if(c=='-') f=-1;c=getchar();}
//	while(c>='0'&&c<='9') x=x*10+c-'0',c=getchar();
//	return x*f;
//}
//void write(int x)
//{
//	if(x<0) putchar('-'),x=-x;
//	if(x>9) write(x/10);
//	putchar(x%10+'0');
//}
int read(int i,int j)
{
	cout<<i<<" "<<j<<endl;
	int x;
	cin>>x;
	return x;
}
int find(int x)
{
	for(int i=x;i<=n;i++)
		if(isok[i]) return i;
}
bool check(int x)
{
	for(int i=x;i<=n;i++)
		isok[i]=0;
	while(true)
	{
		k2=read(x,x);
		if(k2==n) return true;
		isok[x]^=1;
		int now=k2,last=k1;
		k1=k2;
		if(now==last+1)
		{
			return false;
		}
		else if(now==last-1)
		{
			k2=read(x,x);
			if(k2==n) return true;
			k1=k2;
			return false;
		}
		int nxt=find(x)+1;
		k2=read(x,nxt);
		if(k2==n) return true;
		k1=k2;
		isok[nxt]^=1;
	}
}
//function_end
//solve_begin
void solve()
{
	cin>>n>>k1;
	if(k1==n)
		return;
	for(int i=1;i<=n;i++)
	{
		if(check(i))
			return;
	}
}
//solve_end
//main_begin
signed main()
{
//	fastios
	int T=1;
//	cin>>T;
	while(T--)
		solve();
}
//main_end