#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  int p1, p2, n;
  cin >> p1 >> p2 >> n;
  map<int, int> cnt;
  rep(i, n) {
    int r;
    cin >> r;
    cnt[r]++;
  }
  int ans = 0;
  for (auto [k, v] : cnt) {
    ans += (p1 + p2) * (v - 1);
  }
  cout << ans << endl;
  return 0;
}