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

const ll mod = ll(1e9) + 7;
const int INF = 1<<29;

int main(){
    int p1,p2,n;
    cin >> p1 >> p2 >> n;
    map<int,int> r;
    int a;
    rep(i,n){
        cin >> a;
        r[a]++;
    }
    int ans = 0;
    for (auto x:r){
        if (x.first!=1) ans += (p1 + p2) * (x.second - 1);
    }
    cout << ans << endl;
    return 0;
}