B0044.cpp

// Problem Code: COPS

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int copsAndThief(int x, int y, vector<int> M) {
	vector<bool> houses(101);
	int lower, upper, prod = x*y;
	houses[0] = true;
	for(int i=0 ; i<M.size() ; i++) {
		lower = max(1, M[i] - prod);
		upper = min(100, M[i] + prod);
		for(int j=lower ; j<=upper ; j++)
			houses[j] = true;
	}
	return count(houses.begin(), houses.end(), false);
}

int main() {
	int T, M, x, y, num;
	vector<int> cops;
	cin >> T;
	while(T--) {
		cin >> M >> x >> y;
		for(int i=0 ; i<M ; i++) {
			cin >> num;
			cops.push_back(num);
		}
		cout << copsAndThief(x, y, cops) << endl;
		cops.clear();
	}
	return 0;
}