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

typedef long long ll;

struct Node {
	ll x, y;
	ll u;
	ll v;
	bool friend operator < (Node x, Node y) {
		return x.x * y.y > x.y * y.x;
	}
} st;

ll n, m, mx, s, ans, t;
ll a[200100];
ll p[200100];
priority_queue<Node> q;
ll trl[800100];
ll trr[800100];
ll lz1[800100];
ll lz2[800100];
bool vis[200100];

inline void ins(ll x) {
	for (ll i = 1; i <= n; i++) {
		ll v = i;
		st.u = v;
		st.v = x;
		st.x = abs(a[x] - a[v]);
		st.y = abs(x - v);
		q.push(st);
	}
	return;
}

void build(ll l, ll r, ll idx) {
	if (l == r) {
		trl[idx] = 0;
		trr[idx] = m + 1;
	} else {
		ll mid = (l + r) >> 1;
		build(l, mid, idx << 1);
		build(mid + 1, r, idx << 1 | 1);
	}
	return;
}

inline void pd(ll idx) {
	if (lz1[idx]) {
		trl[idx << 1] = lz1[idx << 1] = lz1[idx];
		trl[idx << 1 | 1] = lz1[idx << 1 | 1] = lz1[idx];
		lz1[idx] = 0;
	}
	if (lz2[idx]) {
		trr[idx << 1] = lz2[idx << 1] = lz2[idx];
		trr[idx << 1 | 1] = lz2[idx << 1 | 1] = lz2[idx];
		lz2[idx] = 0;
	}
	return;
}

void upd1(ll l, ll r, ll idx, ll L, ll R, ll x) {
	if (L <= l && r <= R) {
		trl[idx] = x;
		lz1[idx] = x;
	} else {
		pd(idx);
		ll mid = (l + r) >> 1;
		if (L <= mid) {
			upd1(l, mid, idx << 1, L, R, x);
		}
		if (mid < R) {
			upd1(mid + 1, r, idx << 1 | 1, L, R, x);
		}
	}
	return;
}

void upd2(ll l, ll r, ll idx, ll L, ll R, ll x) {
	if (L <= l && r <= R) {
		trr[idx] = x;
		lz2[idx] = x;
	} else {
		pd(idx);
		ll mid = (l + r) >> 1;
		if (L <= mid) {
			upd2(l, mid, idx << 1, L, R, x);
		}
		if (mid < R) {
			upd2(mid + 1, r, idx << 1 | 1, L, R, x);
		}
	}
	return;
}

inline ll qry(ll l, ll r, ll idx, ll x) {
	if (l == r) {
//		cout << "^" << trr[idx] << " " << trl[idx] << endl;
		return trr[idx] - trl[idx];
	} else {
		pd(idx);
		ll mid = (l + r) >> 1;
		if (x <= mid) {
			return qry(l, mid, idx << 1, x);
		} else {
			return qry(mid + 1, r, idx << 1 | 1, x);
		}
	}
}

int main() {
	scanf("%lld%lld", &n, &m);
	a[0] = 0;
	a[n + 1] = m + 1;
	for (ll i = 1; i <= n; i++) {
		scanf("%lld", &a[i]);
	}
	vis[0] = vis[n + 1] = 1;
	ins(0);
	ins(n + 1);
	while (!q.empty()) {
		Node tt = q.top();
		q.pop();
		if (vis[tt.u]) {
			continue;
		}
		ll x = 0;
		if (tt.u < tt.v) {
			for (ll i = tt.u; i <= tt.v; i++) {
				if (vis[i]) {
					x = i - 1;
					break;
				}
				vis[i] = 1;
			}
			for (ll i = x; i >= tt.u; i--) {
				p[++t] = i;
			}
		} else {
			for (ll i = tt.u; i >= tt.v; i--) {
				if (vis[i]) {
					x = i + 1;
					break;
				}
				vis[i] = 1;
			}
			for (ll i = x; i <= tt.u; i++) {
				p[++t] = i;
			}
		}
	}
	build(1, n, 1);
	for (ll i = 1; i <= n; i++) {
		ans += qry(1, n, 1, p[i]);
		upd2(1, n, 1, 1, p[i], a[p[i]]);
		upd1(1, n, 1, p[i], n, a[p[i]]);
	} 
	printf("%lld\n", ans);
	return 0;
}