#include <iostream>
#include <vector>
using namespace std;
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
int a = 0, b = 0, n = 0;
int total = 0;
cin >> a >> b >> n;
vector<int> v1;
for (int i = 0; i < n; i++){
int tmp = 0;
cin >> tmp;
v1.push_back(tmp);
}
for (int j = 0; j < n; j++){
int sec = v1[j] % (a + b);
if (sec < a)
continue;
else if (sec == a){
total += b;
continue;
}
else if (sec > a){
total += b - (sec - a);
continue;
}
}
cout << total;
return 0;
}