#include<bits/stdc++.h>
#define ull unsigned long long
#define ui unsigned int
#define ld long double
#define ll long long
#define lll __int128
#define fi first
#define se second
#define e emplace
#define eb emplace_back
#define db double
#define ef emplace_front
#define pii pair<int,int>
#define pll pair<ll,ll>
#define vi vector<int>
#define vp vector<pii>
#define mp make_pair

//#define LOCALJUDGE
#define int ll
bool ST;
static const ll MOD=1e9+7,Phi=998244352,inv2=499122177,Root=3,iRoot=332748118;
static const ll inf=1073741823,INF=4557430888798830399;
static const double eps=1e-10,pi=3.1415926535;
char in[1<<20],*p1=in,*p2=in;
using namespace std;
//#define getchar() (p1==p2&&(p2=(p1=in)+fread(in,1,1<<20,stdin),p1==p2)?EOF:*p1++)
struct tup{int x,y,z;tup(int X=0,int Y=0,int Z=0){x=X,y=Y,z=Z;}};
namespace FastIO
{
	template<typename T> inline void write(T x,char ch=' ')
	{
		if(is_same<char,T>::value)putchar(x);
		else
		{
			if(x<0)x=-x,putchar('-');
			static char st[25];int top=0;
			do{st[top++]=x%10+'0',x/=10;}while(x);
			while(top)putchar(st[--top]);
		}
		ch!='~'?putchar(ch):0;
	}
	inline void write(const char*x,char ch=' ')
	{
		for(int i=0;x[i]!='\0';++i)putchar(x[i]);
		ch!='~'?putchar(ch):0;
	}
	inline void read(char&s){do s=getchar();while(s=='\n'||s==' ');}
	inline void read(char s[])
	{
		int len=0;char st;
		do st=getchar();while(st=='\n'||st==' ');
		s[++len]=st,st=getchar();
		while(st!='\n'&&st!=' ')s[++len]=st,st=getchar();
		s[++len]='\0';
	}
	template<typename T> inline void read(T &s)
	{
		s=0;char ch=getchar();
		while((ch>'9'||ch<'0')&&ch!='-')ch=getchar();
		bool tf=(ch=='-')&&(ch=getchar());
		while((ch>='0')&&(ch<='9'))s=(s<<1)+(s<<3)+ch-'0',ch=getchar();
		s=(tf?-s:s);
	}
	template<typename T1,typename T2> inline void read(pair<T1,T2> &s){read(s.fi),read(s.se);}
	template<typename T,typename...Args> inline void write(T x,Args...args){write(x,'~'),write(args...);}
	template<typename T,typename...Args> inline void read(T&x,Args&...args){read(x),read(args...);}
}
using namespace FastIO;
namespace MTool
{
	inline int Cadd(int a,int b){return a+b>=MOD?a+b-MOD:a+b;}
	inline int Cdel(int a,int b){return a-b<0?a-b+MOD:a-b;}
	inline int Cmul(int a,int b){return 1ll*a*b%MOD;}
	inline int sqr(int a){return 1ll*a*a%MOD;}
	inline void Madd(int&a,int b){a=(a+b>=MOD?a+b-MOD:a+b);}
	inline void Mdel(int&a,int b){a=(a-b<0?a-b+MOD:a-b);}
	inline void Mmul(int&a,int b){a=1ll*a*b%MOD;}
	template<typename T> inline bool Mmax(T&a,T b){return a<b?a=b,1:0;}
	template<typename T> inline bool Mmin(T&a,T b){return a>b?a=b,1:0;}
	template<typename...Args> inline void Madd(int&a,int b,Args...args){Madd(a,b),Madd(a,args...);}
	template<typename...Args> inline void Mmul(int&a,int b,Args...args){Mmul(a,b),Mmul(a,args...);}
	template<typename...Args> inline void Mdel(int&a,int b,Args...args){Mdel(a,b),Mdel(a,args...);}
	template<typename...Args> inline int Cadd(int a,int b,Args...args){return Cadd(Cadd(a,b),args...);}
	template<typename...Args> inline int Cmul(int a,int b,Args...args){return Cmul(Cmul(a,b),args...);}
	template<typename...Args> inline int Cdel(int a,int b,Args...args){return Cdel(Cdel(a,b),args...);}
	template<typename...Args,typename T> inline bool Mmax(T&a,T b,Args...args){return Mmax(a,b)|Mmax(a,args...);}
	template<typename...Args,typename T> inline bool Mmin(T&a,T b,Args...args){return Mmin(a,b)|Mmin(a,args...);}
	inline int power(int x,ll y){int s=1;for(;y;y>>=1,Mmul(x,x))if(y&1)Mmul(s,x);return s;}
}
using namespace MTool;
namespace WrongAnswer_90
{
	int T,n,top,c[2010];
	tup a[2010];
	void dfs()
	{
		if(top==2)return a[2].z=-1e15,void();
		if(top==1)return;
		tup a1[2010];memcpy(a1,a,sizeof(a));
		int v1,v2;
		write("? ",1,' ',a[3].y,'\n'),fflush(stdout),read(v1);
		if(v1>max(a[1].z,a[3].z))
		{
			a1[2].z=v1-a[1].z-a[3].z;
			for(int i=1;i<top-1;++i)a[i]=a[i+2];
			top-=2,a[1].x=1,a[1].z=v1,dfs();
			for(int i=top+2;i>=3;--i)a[i]=a[i-2];
			a[1]=a1[1],a[2]=a1[2],a[3]=a1[3],top+=2;
		}
		else
		{
			if(top==3)return a[2].z=-1e15,void();
			write("? ",a[3].x,' ',a[5].y,'\n'),fflush(stdout),read(v2);
			if(v2>max(a[5].z,a[3].z))
			{
				a1[4].z=v2-a[3].z-a[5].z;
				for(int i=3;i<top-1;++i)a[i]=a[i+2];
				a[3].z=v2,a[3].x=a[2].y+1,top-=2,dfs();
				for(int i=top+2;i>=5;--i)a[i]=a[i-2];
				a[3]=a1[3],a[4]=a1[4],a[5]=a1[5],top+=2;
			}
			else
			{
				for(int i=2;i<top-1;++i)a[i]=a[i+2];
				top-=2,a[2].x=a[1].y+1,dfs();
				for(int i=top+2;i>=4;--i)a[i]=a[i-2];
				a[2]=a1[2],a[3]=a1[3],a[4].x=a[3].y+1,top+=2;
				a[2].z=-max(a[1].z,a[3].z),a[4].z-=a[2].z;
				assert(-a[4].z>=max(a[3].z,a[5].z));
			}
		}
	}
	inline void mian()
	{
		read(T);int x;
		while(T--)
		{
			read(n),a[top=1]=tup(1,0,1);
			for(int i=1;i<=n;++i)
			{
				write("? ",i,' ',i,'\n'),fflush(stdout);
				read(x),c[i]=x;
				if(x>0)
				{
					if(a[top].z>0)a[top].z+=x;
					else a[top].y=i-1,a[++top]=tup(i,i,x);
				}
				else if(a[top].z>0)a[top].y=i-1,a[++top]=tup(i,i,0);
			}
			a[top].y=n,--a[1].z;
			if(a[top].z==0)a[++top]=tup(n+1,n,inf);dfs();
			write('!');
			for(int i=1;i<=top;++i)
			{
				if(a[i].z>0)for(int j=a[i].x;j<=a[i].y;++j)write(c[j]);
				else{if(a[i].x<=a[i].y)write(a[i].z);for(int j=a[i].x;j<a[i].y;++j)write(0);}
			}
			puts(""),fflush(stdout);
		}
	}
}
bool ED;
signed main()
{
	#ifdef LOCALJUDGE
	freopen("1.in","r",stdin);
	freopen("1.out","w",stdout);
	#endif 
	double st=clock();
	WrongAnswer_90::mian();
	double ed=clock();
	#ifndef LOCALJUDGE
 	cerr<<endl;
	#endif
 	cerr<<"Time: "<<ed-st<<" ms\n";
	#ifdef LOCALJUDGE
 	cerr<<"     ";
	#endif
 	cerr<<"Memory: "<<abs(&ST-&ED)/1024.0/1024.0<<" MB\n";
	return 0;
}