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

#define ll long long
int main() {
  ll N, T;
  cin >> N >> T;
  
  vector<ll> time(N);
  
  ll ans = 0;
  for (int i = 0; i < N; i++) {
    cin >> time[i];
  }
  
  for (int i = 0; i < N-1; i++) {
    if (time[i+1] - time[i] < T) {
      ans += time[i+1]- time[i];
    } else {
      ans += T;
    }
  }
  
  ans += T;
  
  cout << ans << endl;
  
  
  
  
  
  
}
#include<bits/stdc++.h>
using namespace std;

int main(){
  int n;
  char str[1002],cmp[8]="Hoshino";
  scanf("%d%c",&n,&str[0]);
  for(int i=0;i<n;i++){
    gets(str);
    int cnt=0;
    int j=0;
    while(str[j]!='\0'){
      if(str[j]==cmp[cnt])cnt++;
      else cnt=0;
      if(str[j]==cmp[cnt])cnt++;
      if(cnt==7){str[j]='a';cnt=0;}
      j++;
    }
    puts(str);
  }
}