#line 1 "main_a.cpp"
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cctype>
#include <chrono>
#include <cmath>
#include <complex>
#include <cstdint>
#include <cstdlib>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <type_traits>
#include <unordered_map>
#include <utility>
#include <vector>

/* template start */

#line 2 "/home/imperi/cp-library/lib/utility/type_alias.hpp"

#line 4 "/home/imperi/cp-library/lib/utility/type_alias.hpp"

using u64 = std::uint64_t;
using u32 = std::uint32_t;
using u16 = std::uint16_t;
using u8 = std::uint8_t;

using i64 = std::int64_t;
using i32 = std::int32_t;
using i16 = std::int16_t;
using i8 = std::int8_t;

using usize = std::size_t;
using isize = std::ptrdiff_t;

i64 operator"" _i64(unsigned long long num) { return i64(num); }

u64 operator"" _u64(unsigned long long num) { return u64(num); }
#line 33 "main_a.cpp"

#define rep(i, a, b) for (i64 i = (a); (i) < (b); (i)++)
#define all(i) i.begin(), i.end()

#ifdef LOCAL
#define debug(...)                                                    \
  std::cerr << "LINE: " << __LINE__ << "  [" << #__VA_ARGS__ << "]:", \
      debug_out(__VA_ARGS__)
#else
#define debug(...)
#endif

void debug_out() { std::cerr << std::endl; }

template <typename Head, typename... Tail>
void debug_out(Head h, Tail... t) {
  std::cerr << " " << h;
  if (sizeof...(t) > 0) std::cerr << " :";
  debug_out(t...);
}

template <typename T1, typename T2>
std::ostream& operator<<(std::ostream& os, std::pair<T1, T2> pa) {
  return os << pa.first << " " << pa.second;
}

template <typename T>
std::ostream& operator<<(std::ostream& os, std::vector<T> vec) {
  for (std::size_t i = 0; i < vec.size(); i++)
    os << vec[i] << (i + 1 == vec.size() ? "" : " ");
  return os;
}

template <typename T1, typename T2>
inline bool chmax(T1& a, T2 b) {
  return a < b && (a = b, true);
}

template <typename T1, typename T2>
inline bool chmin(T1& a, T2 b) {
  return a > b && (a = b, true);
}

template <typename Num,typename Func = std::multiplies<Num>>
constexpr Num mypow(Num a, u64 b, Num id = 1,Func mul =Func() ) {
  if (b == 0) return id;
  Num x = id;
  while (b > 0) {
    if (b & 1) x  = mul(x,a);
    a = mul(a,a);
    b >>= 1;
  }
  return x;
}

/* template end */

int main() {
  std::cin.tie(nullptr);
  std::cerr.tie(nullptr);
  std::ios::sync_with_stdio(false);

  i64 testcase;
  std::cin>>testcase;

  while(testcase--){
    i64 n;
    std::cin>>n;

    std::string s;
    std::cin>>s>>s>>s;

    rep(i,0,n)std::cout<<0;
    rep(i,0,n)std::cout<<1;
    std::cout<<0<<"\n";
  }

  return 0;
}

#pragma GCC optimize ("O2")
#pragma GCC target ("avx")
//#include<bits/stdc++.h>
#include<iostream>
#include<cstring>
//#include<atcoder/all>
//using namespace atcoder;

using namespace std;
typedef long long ll;
#define rep(i, n) for(int i = 0; i < (n); i++)
#define rep1(i, n) for(int i = 1; i <= (n); i++)
#define co(x) cout << (x) << "\n"
#define cosp(x) cout << (x) << " "
#define ce(x) cerr << (x) << "\n"
#define cesp(x) cerr << (x) << " "
#define pb push_back
#define mp make_pair
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define Would
#define you
#define please

char cn[1200010];
char* ci = cn, * di = cn;
const ll ma0 = 1157442765409226768;
const ll ma1 = 1085102592571150095;
const ll ma2 = 71777214294589695;
const ll ma3 = 281470681808895;
const ll ma4 = 4294967295;
inline int getint() {
	ll tmp = *(ll*)ci;
	int dig = 68 - __builtin_ctzll((tmp & ma0) ^ ma0);
	tmp = tmp << dig & ma1;
	tmp = tmp * 10 + (tmp >> 8) & ma2;
	tmp = tmp * 100 + (tmp >> 16) & ma3;
	tmp = tmp * 10000 + (tmp >> 32) & ma4;
	ci += 72 - dig >> 3;
	return tmp;
}

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	fread(cn, 1, 1200010, stdin);
	int T = getint();

	rep(t, T) {
		int N = getint();

		rep(i, N)* di++ = '0';
		rep(i, N)* di++ = '1';
		*di++ = '0';
		*di++ = '\n';
		ci += 6 * N + 3;
	}
	fwrite(cn, 1, di - cn, stdout);

	Would you please return 0;
}