#include <iostream>
#include <algorithm>
using namespace std;
int main(void){
  int n,i;
  long a,b,x[100010],ans=0;
  cin >> n >> a >> b;
  for (i=0;i<n;i++) cin >> x[i];
  for (i=0;i<n-1;i++){
    ans+=min(a*(x[i+1]-x[i]),b);
  }
  cout << ans << endl;
  return 0;
}