#include <iostream>
#include <vector>
#include <queue>

using namespace std;
vector<pair<int,int>>v[100000];

struct node{
  int idx;
  int dist;
  node(){}
  node(int _idx,int _dist){
    idx=_idx;
    dist=_dist;
  }
  bool operator < (const node & tmp)const{
    return dist > tmp.dist;
  }
};
void dijkstra(int s,int n){
vector<bool>visited(n,false);
vector<int>dist(n,2e9);

dist[s]=0;
priority_queue<node>pq;
pq.push(node(s,0));

  while(!pq.empty()){
    node c = pq.top();
    pq.pop();
    if(visited[c.idx]==true){
        continue;
    }
    else{
        visited[c.idx]=true;
    }

    for(int i = 0;i<v[c.idx].size();i++){
        int sosed = v[c.idx][i].first;
        int dist2 = v[c.idx][i].second;

        if(visited[sosed]==false && c.dist + dist2 < dist[sosed]){
          dist[sosed] = c.dist + dist2;
          pq.push(node(sosed,dist[sosed]));
        }
    }
  }
 cout<<dist[n-1]<<endl;
}

int main()
{
    int n,V;
    cin>>n>>V;
    vector<int>x(n);
    for(int i = 0;i<n;i++){
        cin>>x[i];
    }
    for(int i = 0;i<n;i++){
        if(i>0){
          v[i].push_back(make_pair(i-1,1));
            v[i - 1].push_back(make_pair(i,1));

        }
        if(i + 1 < n){
          v[i].push_back(make_pair(i+1,1));
            v[i + 1].push_back(make_pair(i,1));

        }
        for(int j = 0;j<n;j++){
            if(x[i]==x[j]){
                v[i].push_back(make_pair(j,V));
                v[j].push_back(make_pair(i,V));

            }
        }
    }
    dijkstra(0, n);
    return 0;
}