
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define dump(...)
#endif
#define endl "\n"
#define ll long long
#define FOR(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define REP(i, x) for (int i = 0; i < (int)(x); i++)
#define REPS(i, x) for (int i = 1; i <= (int)(x); i++)
#define RREP(i, x) for (int i = ((int)(x)-1); i >= 0; i--)
#define RREPS(i, x) for (int i = ((int)(x)); i > 0; i--)
#define INF 2147483647
#define LLINF 9223372036854775807LL
#define vi vector<int>
#define vvi vector<vector<int>>
#define pi pair<int, int>
#define ALL(a) (a).begin(), (a).end()
#define BIT(n) (1LL << (n))
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end()) //sortしてからつかうこと
constexpr ll MOD = 1e9 + 7;
int dx[8] = {1, 0, -1, 0, 1, 1, -1, -1};
int dy[8] = {0, 1, 0, -1, 1, -1, 1, -1};
ll A, B, C, D, E, F, G, H, N, M, L, K, P, Q, R, W, X, Y, Z;
string S, T;
ll ans = 0;

template <typename T>
istream &operator>>(istream &is, vector<T> &vec) {
    for (T &x : vec)
        is >> x;
    return is;
}

signed main() {
    ll T;
    cin >> N >> T;
    vi t(N);
    cin >> t;
    REP(i, N - 1) {
        if (t[i + 1] - t[i] > T)
            ans += T;
        else
            ans += t[i + 1] - t[i];
    }
    ans += T;
    cout << ans << endl;
}
#include <bits/stdc++.h>
const double PI = acos(-1);
#define rep(i, n) for (int i = 0; i < (int)(n); i++ )
using namespace std;
int findSumOfDigits(int n) {
  int sum = 0;
  while (n > 0) { // n が 0 になるまで
    sum += n % 10;
    n /= 10;
  }
  return sum;
}
int main(){
    int x, y, z;
    cin >> x >> y >> z;
    int ansx, ansy, ansz;
    ansx = y;
    ansy = x;
    x = y;
    y = ansy;
    ansx = z;
    ansz = x;
    cout << ansx << " " << ansy << " " << ansz << endl;
}