#include <bits/stdc++.h>

using namespace std;

#define ll long long int
#define pb push_back
#define mp make_pair
#define INF (ll)(1e18)
#define inf 0x7fffffff
#define inff 100000
#define ff first
#define ss second
#define sz(x) ((int) (x).size())
#define fast cin.sync_with_stdio(0);cin.tie(0)
#define rep(i,N) for(int i = 0;i < N;i++)
#define frep(i,a,b) for(int i = a;i <= b;i++)
#define pii pair<int , int>
#define pll pair<ll , ll>
#define vii vector<int>
#define vpii vector< pii >
#define fill(A,v) memset(A,v,sizeof(A))
#define setbits(x) __builtin_popcountll(x)
#define print(A,j,k) for(int ii=j;ii<k;ii++)cout<<A[ii]<<" ";cout<<"\n"
#define all(x) (x).begin(), (x).end()
#define gcd __gcd
#define SQRT 350
#define CASES int t;cin>>t;while(t--)
#define FILE freopen("inp.txt" , "r" , stdin);
#define ld long double

const int MOD = 1e9 + 7;
const int N = 1e6 + 5;

ll n , x;
ll cost[2005][2005];
ll Dist[N];
ll A[N] , change[N];
int vis[N];

/*
0 -> 10
1 -> 20
2 -> 1 + 30
3 -> 1
*/

int main(int argc, char const *argv[])
{
    fast;

    cin >> n >> x;

    set< pair<ll , int> > S;
    for(int i = 0;i < n;i++) {
        cin >> A[i];
        Dist[i] = A[i];
        S.insert( {Dist[i] , i});
    }

    ll current = 0;

    while (S.size() > 0) {

        auto it = S.begin();
        int source = it -> ss;
        // cout << "source " << source << '\n';
        vis[source] = 1;
        S.erase(it);
        int nxt;
        if (source == n - 1)
            nxt = 0;
        else
            nxt = source + 1;


        if (change[source] + 1 <= current) {
            if (Dist[nxt] > Dist[source]) {
                change[nxt] = change[source] + 1;
                Dist[nxt] = Dist[source];
                if (vis[nxt] == 0) {
                    S.insert( {Dist[nxt] , nxt});
                }
            }
        }
        else {
            if (Dist[nxt] > Dist[source] + (change[source] + 1 - current) * x ) {
                change[nxt] = change[source] + 1;
                Dist[nxt] = Dist[source] + (change[source] + 1- current) * x;
                if (vis[nxt] == 0) {
                    S.insert( {Dist[nxt] , nxt});
                }
            }
        }
        current = max(current , change[nxt]);
    }

    // print(Dist , 0 , n);

    ll ans = 0;
    for(int i = 0;i < n;i++)
        ans += Dist[i];
    cout << ans << '\n';

    return 0;
}