#include using namespace std; using ll = long long; using ull = unsigned long long; using ld = long double; template using vc = vector; template using vvc = vc>; using pi = pair; using vi = vc; using vvi = vvc; #define rep(i,a,b) for (int i = a; i < b; i++) #define irep(i,a,b) for (int i = a; i > b; i--) #define print(n) cout << n << endl #define rup(a,b) (a+b-1)/b void solve(){ string x,y;cin>>x>>y; if(x+yy+x) print("X"); else{ if(x.size()>y.size()) print("X"); else print("Y"); } return; } int main(){ cout << fixed << setprecision(15); int T; cin >> T; rep(i,0,T) solve(); //system("pause"); return 0; }