#include<bits/stdc++.h>
using namespace std;
using Int = long long;
//INSERT ABOVE HERE
signed main(){
  Int p1,p2;
  cin>>p1>>p2;
  Int n;
  cin>>n;
  string s;
  map<string, Int> m;
  for(Int i=0;i<n;i++){
    cin>>s;
    m[s]++;
  }
  Int ans=0;
  for(auto p:m) ans+=p.second-1;
  cout<<ans*(p1+p2)<<endl;
  return 0;
}