#include <cstdio>
#include <algorithm>
using namespace std;

typedef long long ll;

int main(){
  int N, A, B, x1, x2;
  ll ans = 0;
  scanf("%d %d %d %d", &N, &A, &B, &x1);
  for(int i=1; i<N; i++){
    scanf("%d", &x2); ans+=min((x2-x1)*(ll)A, (ll)B);
    x1 = x2;
  }
  printf("%lld\n", ans);
  return 0;
}
