#include <bits/stdc++.h>
using namespace std;
using LL = long long;
using PII = pair<int, int>;

void solve() {
    int n, x;
    cin >> n >> x;
    vector<int> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    priority_queue<PII, vector<PII>, greater<>> q;
    vector<int> dis(n, 1e9), vis(n);
    dis[0] = 0;
    q.emplace(0, 0);

    while (!q.empty()) {
        auto [d, now] = q.top();
        q.pop();
        if (vis[now]) {
            continue;
        }
        vis[now] = 1;
        for (int i = 0; i < n; i++) {
            int nxt = (i + a[now]) % n;
            if (d + i + 1 < dis[nxt]) {
                dis[nxt] = d + i + 1;
                q.emplace(dis[nxt], nxt);
            }
        }
    }

    cout << dis[x] << "\n";
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}