#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
int T;
string s;
int main()
{
cin>>T;
while(T--)
{
int n;
cin>>n;
cin>>s;
string ans;
int i;
for(i=0;i<s.size()-1;i++)
{
if(s[i]<=s[i+1]) ans+=s[i];
else break;
}
for(int j=i+1;j<s.size();j++) ans+=s[j];
cout<<ans<<endl;
}
}