#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main() {
    int N;
    ll A, B;
    cin >> N >> A >> B;
    ll X[N];
    for (int i = 0; i < N; i++) {
        cin >> X[i];
    }
    ll e[N- 1];
    for (int i = 0; i < N - 1; i++) {
        e[i] = X[i + 1] - X[i];
    }
    ll ans = 0;
    for (int i = 0; i < N - 1; i++) {
        if (e[i] * A < B) ans += e[i] * A;
        else ans += B;
    }
    cout << ans << "\n";
    return 0;
}
#include <bits/stdc++.h>
using namespace std;
#define ll long long 
#define endl "\n"
#define pb push_back
#define f(i,n) for(i=0;i<n;i++)
#define F(i,a,b) for(i=a;a<=b;i++)
#define arr(a,n) for( i=0;i<n;i++)cin>>a[i];
#define fi first
#define se second
#define mp make_pair
#define mod 1000000007
#define YES cout<<"YES"<<endl;
#define Yes cout<<"Yes"<<endl;
#define NO cout<<"NO"<<endl;
#define No cout<<"No"<<endl;
#define yes cout<<"yes"<<endl;
#define no cout<<"no"<<endl;
#define vi vector<ll>
#define ed end()
#define bg begin()
#define sz size()
#define ln length()
#define s() sort(a,a+n);
#define sr() sort(a,a+n,greater<ll>());
#define v()  sort(v.begin(),v.end());
#define vr() sort(v.begin(),v.end(),greater<ll>());
#define mod 1000000007
#define fast() ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
ll gcd(ll a, ll b){if(!b)return a;return gcd(b, a % b);}
ll power(ll x,ll y,ll p){ll res=1;x%=p;while(y>0){if(y&1)res=(res*x)%p;y=y>>1;x=(x*x)%p;}return res;}
int main() {
    /*#ifndef ONLINE_JUDGE
        // for getting input from input.txt
        freopen("input.txt", "r", stdin);
        // for writing output to output.txt
        freopen("output.txt", "w", stdout);
    #endif*/
        /* 
        Ofcourse it's Hard.
        It's supposed to be Hard.
        If it's easy everyone would do it.
        HARD IS WHAT MAKES IT GREAT

        YESTERDAY U SAID TOMORROW

        SLOWLY BECOMING THE PERSON I 
        SHOULD HAVE BEEN A LONG TIME AGO

        SAME TASK CAN'T BE FOUND DIFFICULT TWICE

        BTBHWSITW

        SPRH TU KAB P

        CP IS ALL ABOUT THINKING 
        YOU HAVE MUCH MORE POTENTIAL THAN U THINK

        AJIT SHIDDAT 10

        UR DAILY ROUTINE 


        */

fast();
//ll t;cin>>t;while(t--)
{
  ll n,t,s=0;
  cin>>n>>t;
  ll a[n];
  for(int i=0;i<n;i++)
    {
      cin>>a[i];
    }
    for(int i=1;i<n;i++)
    {
        s+=min(t,a[i]-a[i-1]);
    }  
    cout<<s+t<<endl;

}
return 0;
}