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

ll P1, P2, N, R[100];

int main(void) {
  cin >> P1 >> P2 >> N;
  REP(i, 0, N) cin >> R[i];

  map<ll, ll> mp;
  REP(i, 0, N) mp[R[i]]++;

  ll ans = 0;
  for(auto p : mp) {
    ll k = p.first;
    ll v = p.second;
    ans += (v - 1) * (P1 + P2);
  }
  cout << ans << endl;
}