#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000000000

struct rolling_hash{

	long long t_hash;
	static const long long MOD = (1LL<<61)-1;
	static const long long b = 123456;
	long long sz;
	
	rolling_hash(){		
		sz = 0;
		t_hash = 0;
	}
	
	rolling_hash(char c){
		sz = 1;
		t_hash = b*c;
	}

	long long mul(__int128 x,__int128 y){
		__int128 t = x*y;
		t = (t>>61) + (t&MOD);
		
		if(t>=MOD)t -= MOD;
		return t;
	}
	
	long long get_pow(long long sz){
		
		long long cur = b,ret = 1;
		
		rep(i,40){
			
			if((sz>>i)&1){
				ret = mul(ret,cur);
				sz -= (1LL<<i);
			}
			cur = mul(cur,cur);
			if(sz==0)break;
		}
		return ret;
	}
	
	rolling_hash &operator+=(const rolling_hash &another){
		
		(*this).t_hash = mul((*this).t_hash,get_pow(another.sz));
		(*this).t_hash += another.t_hash;
		if((*this).t_hash>=MOD)(*this).t_hash -= MOD;
			
		(*this).sz += another.sz;
		
		return (*this);
	}
	
	rolling_hash operator+(const rolling_hash &another)const{
		return (rolling_hash(*this)+=another);
	}
	
	rolling_hash &operator-=(const rolling_hash &another){

		(*this).t_hash += MOD - mul(another.t_hash,get_pow((*this).sz-another.sz));
		if((*this).t_hash>=MOD)(*this).t_hash -= MOD;
			
		(*this).sz -= another.sz;

		return (*this);
	}
	
	rolling_hash operator-(const rolling_hash &another)const{
		return (rolling_hash(*this)-=another);
	}
	
	bool operator<(const rolling_hash &another)const{
		if((*this).t_hash!=another.t_hash)return (*this).t_hash<another.t_hash;
		return (*this).sz<another.sz;
	}
	
	bool operator==(const rolling_hash &another)const{
		return ((*this).t_hash==another.t_hash && (*this).sz==another.sz);
	}

	
};

//vector<long long> rolling_hash::power;


int main() {
    
	int _t;
	cin>>_t;
	
	rep(_,_t){
		
		string x,y;
		cin>>x>>y;
		int n  =x.size(),m = y.size();
		vector<rolling_hash> Rx(n+1),Ry(m+1);
		rep(i,n){
			Rx[i+1] = rolling_hash(x[i]);
			Rx[i+1] = Rx[i] + Rx[i+1];
		}
		rep(i,m){
			Ry[i+1] = rolling_hash(y[i]);
			Ry[i+1] = Ry[i] + Ry[i+1];
		}
	
		vector<rolling_hash> dpx(40),dpy(40);
		dpx[0] = Rx.back();
		dpy[0] = Ry.back();
		for(int i=1;i<40;i++){
			dpx[i] = dpx[i-1] + dpx[i-1];
			dpy[i] = dpy[i-1] + dpy[i-1];
		}
		long long L = lcm(n,m)+1;
		long long ok = 0,ng = L + 1;
		
		while(ng-ok>1LL){
			long long mid = (ok+ng)/2;
			
			rolling_hash X,Y;
			rep(i,40){
				if(((mid/n)>>i)&1)X += dpx[i];
				if(((mid/m)>>i)&1)Y += dpy[i];
			}
			X += Rx[mid%n];
			Y += Ry[mid%m];
			if(X==Y)ok = mid;
			else ng = mid;
		}
		//cout<<ok<<endl;
		if(ok==L){
			if(n>m)cout<<'X'<<endl;
			else cout<<'Y'<<endl;
		}
		else{
			if(x[ok%n]>y[ok%m])cout<<"X"<<endl;
			else cout<<"Y"<<endl;
		}
			
		
		
	}
    return 0;
}