#include <bits/stdc++.h>
using namespace std;
//bool cmp(pair<int, int>a, pair<int, int>b){if(a.first==b.first) return a.second > b.second;  else return a.first<b.first;   }
//bool valid(int i, int j){ return 0 <= i&&i < n && 0 <= j&&j < m; }
#define ll long long
#define MEMSET_INF 127
#define MEMSET_HALF_INF 63
#define fi first
#define se second
#define mp make_pair
#define siz 10

typedef pair<int,int> pii;

int n;
string s;
int main(){
      ios_base::sync_with_stdio(0);

      //freopen("milano.in","r",stdin);
     //freopen("output.txt","w",stdout);
    //memset(dist, MEMSET_INF, sizeof dist);
   //memset (dp_memo, -1, sizeof dp_memo);

    int t; cin>>t;

    while(t--){
         cin>>n;

        int arr[200005];  int cnt[15]; int ans[200005];
        vector<int>idx1,idx2;
        memset(cnt,0,sizeof cnt);
        int mn=1000;

        cin>>s;

        for(int i=0;i<s.size();i++){
                cout<<i<< ' ';
            int x = (int)s[i] - (int)('0');
            cnt[x]++;
            arr[i]=x;
            mn=min(mn,x);
        }
        cout<<'\n';
        if(n==1){
            cout<<1<<'\n';
            continue;
        }



        for(int i=0;i<n;i++){
            if(cnt[mn]==0){
                for(int i=mn;i<10;i++){
                    if(cnt[i]>0){
                        mn=i;
                        break;
                    }
                }
            }

            if(arr[i]>mn){
                ans[i]=2;
                cnt[arr[i]]--;
                idx2.push_back(i);
            }
            else if(arr[i]==mn){
                ans[i]=1;
                cnt[arr[i]]--;
                idx1.push_back(i);
            }
        }

        int last=0;
        bool ok=true;
        for(int i=1;i<idx1.size();i++){
            if(arr[idx1[i]]<arr[idx1[i-1]]){
                ok=false; break;
            }
            last=idx1[i];
        }
        if(arr[idx2[0]]<arr[last])
            ok=false;

        for(int i=1;i<idx2.size();i++){
            if(arr[idx2[i]]<arr[idx2[i-1]])
                ok=false;
        }

        if(!ok){
            printf("-");
            continue;
        }

        for(int i=0;i<n;i++) cout<<ans[i];
        cout<<'\n';

    }


    return 0;
}