#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl "\n"
#define ull unsigned long long
#define ms(x, y) memset(x, y, sizeof x);
#define debug(x) cout << #x << " = " << x << endl;
#define ios ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
#define fre                           \
freopen("input.txt", "r", stdin); \
freopen("output.txt", "w", stdout);
const int mod = 998244353;
const int inf = 0x3f3f3f3f3f3f3f3f;
const int N = 1e6 + 10;
const double esp = 1e-6;
const ull MOD1 = 1610612741;
const ull MOD2 = 805306457;
const ull BASE1 = 1331;
const ull BASE2 = 131;
#define pre(i, a, b) for (int i = a; i <= b; i++)
#define rep(i, a, b) for (int i = a; i >= b; i--)
#define all(x) (x).begin(), (x).end()
char *p1, *p2, buf[100000]; // 快读和同步流二者只能选一个
#define nc() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 100000, stdin), p1 == p2) ? EOF : *p1++)
int read()
{
	int x = 0, f = 1;
	char ch = nc();
	while (ch < 48 || ch > 57)
	{
		if (ch == '-')
			f = -1;
		ch = nc();
	}
	while (ch >= 48 && ch <= 57)
		x = x * 10 + ch - 48, ch = nc();
	return x * f;
}
void write(int x)
{
	if (x < 0)
		putchar('-'), x = -x;
	if (x > 9)
		write(x / 10);
	putchar(x % 10 + '0');
	return;
}
void solve()
{
	int n,x;
    cin>>n>>x;
    vector<int>v(n+1),dp(n+1,inf);
    for(int i=0;i<n;i++){
        cin>>v[i];
    }
    dp[v[0]]=min(dp[v[0]],1ll);
    for(int i=1;i<n;i++){
        dp[(v[0]+i)%n]=min(dp[(v[0]+i)%n],i+1);
    }
    for(int i=0;i<n;i++){
        dp[(i+v[i])%n]=min(dp[(i+v[i])%n],dp[i]+1);
    }
    int ans=inf;
    for(int i=1;i<=n;i++){
        if(i>=x){
            ans=min(ans,dp[i]+n-i+x+1);
        }else ans=min(ans,dp[i]+x-i);
    }
    cout<<ans<<endl;
    // for(int i=0;i<n;i++)cout<<dp[i]<<" ";
}
// #define LOCAL
signed main()
{
	ios
	// fre
#ifdef LOCAL
	freopen("in.txt", "r", stdin);
	freopen("out.txt", "w", stdout);
	auto start = std::chrono::high_resolution_clock::now();
#endif
	
	int t = 1;
	// cin >> t;
	while (t--)
		solve();
	
#ifdef LOCAL
	auto end = std::chrono::high_resolution_clock::now();
	cout << "Execution time: "
	<< std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count()
	<< " ms" << '\n';
#endif
	return 0;
}