#include <stdio.h>
#include <algorithm>
#include <string.h>
#include <cctype>
#include <vector>
#include <queue>
#define pb push_back
#define st first
#define nd second
using namespace std;
typedef long long ll;
typedef pair <int, int> Pii;
const int INF=0x3f3f3f3f;
const int cp=1e9+7;
inline int read(){
	char ch=getchar();int x=0, f=1;
	while(!isdigit(ch)){if(ch=='-') f=-1; ch=getchar();}
	while(isdigit(ch)){x=(x<<3)+(x<<1)+ch-'0';ch=getchar();}
	return x*f;
}
inline void write(int x){
    if(x<0) putchar('-'), x=-x;
    if(x>9) write(x/10);
    putchar(x%10+'0');
}
inline int ksm(int a, int b){
	int ret=1;
	for(; b; b>>=1, a=1ll*a*a%cp)
		if(b&1) ret=1ll*ret*a%cp;
	return ret;
}
const int N=(1<<21);
int n, K, dis[N], vis[N];
char s[N];
vector <Pii> G[N];
queue <int> Q;
void clear(){
	for(int i=0; i<=(n>>1); ++i) 
		G[i].clear(), vis[i]=0, dis[i]=INF;
	while(!Q.empty()) Q.pop();
}
bool SPFA(int S){
	Q.push(S);dis[S]=0;
	while(!Q.empty()){
		int x=Q.front();Q.pop();vis[x]=0;
		for(auto v:G[x])
			if(dis[v.st]>dis[x]+v.nd){
				dis[v.st]=dis[x]+v.nd;
				if(!vis[v.st]){
					vis[v.st]=1, Q.push(v.st);
					if(dis[0]<0) return 0;
				} 
			}
	}
	return 1;
}
bool check(int state){
	clear();
	G[0].pb({n>>1, 0}), G[n>>1].pb({0,0});
	for(int S=0; S<(n>>1); ++S)
		for(int bit=0; bit<2; ++bit){
			int T=S|(bit<<(K<<1)), nxt=T>>1, type=T>>K&1;
			int x=1-type, y=type;
			if(T<state) x=(s[T]=='1')-type, y=type-(s[T]=='1');
			G[nxt].pb({S, x}), G[S].pb({nxt, y});
		}
	return SPFA(n>>1);
}
void solve(){
	K=read();scanf("%s", s);n=1<<(K<<1|1);
	int pos=n;
	if(!check(pos)){
		for(pos=n-1; pos>=0; --pos)
			if(s[pos]=='0'){
				s[pos]='1';
				if(check(pos+1)) break;
			} 
	}
	if(pos<0){
		puts("no");
		return ;
	}
	for(++pos; pos<n; ++pos){
		s[pos]='0';
		if(!check(pos+1)) s[pos]='1';
	}
	for(int i=0; i<n; ++i) putchar(s[i]);puts("");
}
signed main(){
	int T=1;
	while(T--) solve();
	return 0;
}