#include<bits/stdc++.h>
using namespace std;
#define fastIO ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define int long long int
#define fi first
#define se second
#define pub push_back
#define pi pair<int,int>
#define all(v) (v).begin(), (v).end()
#define rep(i, l, r) for(int i=(int)(l);i<(int)(r);i++)
#define repd(i, l, r) for (int i=(int)(l);i>=(int)(r);i--)
#define clrg(i, l, r) for(int i=(int)(l);i<(int)(r);i++)vis[i]=0,v[i].clear();
int power(int x, unsigned int y){int res = 1;while (y > 0){ if (y & 1){res = res*x;} y = y>>1;x = x*x;}return res;}
int powermod(int x, unsigned int y, int p){int res = 1;x = x % p;while (y > 0){if (y & 1){res = (res*x) % p;}y = y>>1; x = (x*x) % p;}return res;}
#define print2d(mat,n,m){for(int i=0;i<(int)(n);i++){for(int j=0;j<(m);j++){cout<<mat[i][j]<<" ";}cout<< endl;}}
#define clr(a,x) memset(a,x,sizeof(a))
#define rr(v) for(auto &val:v)
#define print(v) for (const auto itr : v){cout<<itr<<' ';}cout<<"\n";
#define ln length()
#define sz size()
#define mod 1000000007
#define elif else if
int32_t main(){
   double x1,x2,y1,y2;
   cin>>x1>>y1>>x2>>y2;
   if(x1>x2)swap(x1,x2),swap(y1,y2);
   double ans=(y1*(x2-x1))/(y1+y2);
   cout<<fixed<<setprecision(10);
   cout<<x1+ans<<"\n";
   return 0;
}

#include <bits/stdc++.h>
using namespace std;

int solve() {
  int n;
  string s;
  cin >> n >> s >> s >> s;
  cout << string(n, '0') << string(n, '1') << "0\n";
  return 0;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int T = 1;
  cin >> T;
  while (T--) {
    solve();
  }
  return 0;
}
