#include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     long long T;     cin >> T;     while (T--) {       int N;       string S;       cin >> N >> S;       int Who = -1;       string Ans1 =   , Ans2 =   ;       for (int i = 0; i < N; i++) {         if (S[i] ==  2  && !(~Who)) {           Ans1.push_back( 1 );           Ans2.push_back( 1 );         } else if (S[i] ==  2  && ~Who) {           Ans1.push_back( 0 );           Ans2.push_back( 2 );         } else if (S[i] ==  0 ) {           Ans1.push_back( 0 );           Ans2.push_back( 0 );         } else {           if (~Who) {             Ans1.push_back( 0 );             Ans2.push_back( 1 );           } else {             Ans1.push_back( 1 );             Ans2.push_back( 0 );             Who = 1;           }         }       }       cout << Ans1 <<   n  << Ans2 <<   n ;     }     return 0;   }   