#include

#include <bits/stdc++.h>

```
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL)
#define ll long long
using namespace std;
int main() {
fast;
ll T;
cin >> T;
while (T--) {
ll X, Y, N, K;
cin >> X >> Y >> N >> K;
bool found = false;
for (ll i = 0; i < N; i++) {
ll Pi, Ci;
cin >> Pi >> Ci;
if (Pi >= X - Y && Ci <= K)
found = true;
}
cout << (found ? "LuckyChef" : "UnluckyChef") << '\n';
}
return 0;
}
```