#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);

    int p1,p2; cin >> p1 >> p2;
    int N; cin >> N;
    vector<int> room(1000, 0);
    rep(i,N){
        int r; cin >> r;
        room[r]++;
    }
    ll ans = 0;
    rep(i,1000) if(room[i] > 0) ans += (room[i] - 1) * (p1 + p2);
    cout << ans << endl;
}