#include<iostream>
#include<algorithm>
#include<stdlib.h>
#include<string.h>
#include<iomanip>
#include<math.h>
#include<bits/stdc++.h>
using namespace std;
int main()
{
int n,cnt=0;
cin>>n;
string s;
cin>>s;
for(int i=0;i<n;i++)
{
if(s[i]=='1')
{
cnt++;
}
}
if(cnt==0)
{
cout<<s<<endl;
}
else
{
char ar[10000000];
ar[0]='1';
for(int i=1;i<(n+1-cnt);i++)
{
ar[i]='0';
}
cout<<ar<<endl;
}
return 0;
}
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