#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;

int Tn,N,i,fl;
pair<int,string>a[100005];

int main (int argc, char * const argv[]) {
	ios_base::sync_with_stdio(0);
	cin>>Tn;
	for(;Tn;Tn--){
		cin>>N;
		for(i=1;i<=N;i++)cin>>a[i].second>>a[i].first;
		sort(a+1,a+N+1); // sort all the players
		for(fl=0,i=1;i<=N;i++){
			fl=0;
			// in order to check the uniqueness in the sorted list is just sufficient to check two neighbors
			if(i==1||a[i].first!=a[i-1].first)fl+=1;
			if(i==N||a[i].first!=a[i+1].first)fl+=2;			
			if(fl==3){ // if the number if unique, then it's a result
				cout<<a[i].second<<endl;
				break;
			}
		}
		if(fl!=3)cout<<"Nobody wins."<<endl; // if nobody wins
	}
    return 0;
}