#include <bits/stdc++.h>

using namespace std;

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)
#define unless(p) if(!(p))
#define until(p) while(!(p))

using ll = long long;
using P = std::tuple<int,int>;

const int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1}, dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};

int p1, p2, N;
map<int, int> _m;

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    std::cin >> p1 >> p2 >> N;

    for(int i=0;i<N;++i){
        int r;
        std::cin >> r;

        ++_m[r];
    }

    int res = 0;
    for(auto &p : _m){
        int n;
        tie(ignore, n) = p;

        res += (n - 1) * (p1 + p2);
    }

    std::cout << res << std::endl;
}