#include <iostream>
#include <set>
using namespace std;
int main(void) {
	int p1, p2, n, r;
	cin >> p1 >> p2 >> n;
	set<int> st;
	for (int i = 0; i < n; ++i) {
		cin >> r;
		st.insert(r);
	}
	int diff = n - st.size();
	cout << p1 * diff + p2 * diff << endl;
	return 0;
}