#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>
using namespace __gnu_pbds;

#if !ONLINE_JUDGE
#define debug
#endif

using namespace std;
 
/*******  All Required define Pre-Processors and typedef Constants *******/
#define mem(a, b) memset(a, (b), sizeof(a))
#define repd(i,k) for(int i=k;i>=0;i--)
#define rep(i,k) for(int i=0;i<k;i++)
#define repn(i,k1,k2) for(ll i=k1;i<k2;i++)
#define sz(x) (ll)(x).size()
#define ff first
#define ss second

#define all(cont) cont.begin(), cont.end()
#define rall(cont) cont.end(), cont.begin()
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define INF (int)1e9
#define EPS 1e-9
#define PI 3.1415926535897932384626433832795
#define MOD 1000000007
#define ee6 (ll)1000001
#define ee5 (ll)100001

#define trav(a, v) for(auto& a : v)

#define tt ll t;cin>>t; while(t--)
typedef long long int ll;
 
typedef pair<ll, ll> pr;
typedef vector<ll> vi;
typedef vector<string> vs;
typedef vector<pr> vpr;
typedef vector<vpr>vvpr;
typedef vector<vi> vvi;

//*X.find_by_order(2) element at index=2
//X.order_of_key(1) how many elements strictly less than 1

template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag,
    tree_order_statistics_node_update>;

#ifdef debug
#define dbg(...) { cerr<<"[ "; dump(#__VA_ARGS__, __VA_ARGS__);}
#undef endl
template <typename Arg1,typename Arg2>
ostream& operator << (ostream& out, const pair<Arg1,Arg2> &x) {
    return out<<"("<<x.ff<<","<<x.ss<<")";
}
 
template <typename Arg1>
ostream& operator << (ostream& out, const vector<Arg1> &a) {
    out<<"[";for(const auto &x:a)out<<x<<",";return out<<"]";
}
 
template <typename Arg1>
ostream& operator << (ostream& out, const set<Arg1> &a) {
    out<<"[";for(const auto &x:a)out<<x<<",";return out<<"]";
}
 
template <typename Arg1,typename Arg2>
ostream& operator << (ostream& out, const map<Arg1,Arg2> &a) {
    out<<"[";for(const auto &x:a)out<<x<<",";return out<<"]";
}
 
template <typename Arg1,typename Arg2>
ostream& operator << (ostream& out, const unordered_map<Arg1,Arg2> &a) {
    out<<"[";for(const auto &x:a)out<<x<<",";return out<<"]";
} 
 
template <typename Arg1>
void dump(const string name, Arg1&& arg1){
    cerr << name << " : " << arg1 << " ] " << endl;
}
 
template <typename Arg1, typename... Args>
void dump(const string names, Arg1&& arg1, Args&&... args){
    const string name = names.substr(0,names.find(','));
    cerr<<name<<" : "<<arg1<<" | ";
    dump(names.substr(1+(int)name.size()), args...);
}
#else
    #define dbg(args...)
#endif
 
ll powmod(ll x, ll y) 
{ 
    ll res = 1;  
    x = x % MOD;
    while (y > 0) 
    { 
        if (y & 1) 
            res = (res*x) % MOD; 
        y = y>>1; // y = y/2 
        x = (x*x) % MOD;   
    } 
    return res; 
} 

struct FT {
    vector<ll> s;
    FT(ll n) : s(n) {}
    void update(ll pos, ll dif) { // a[pos] += dif
        
        for (; pos < sz(s); pos |= pos + 1) s[pos] += dif;
    }
    ll query(ll pos) { // sum of values in [0, pos]
        pos++;
        ll res = 0;
        for (; pos > 0; pos &= pos - 1) res += s[pos-1];
        return res;
    }
    void update(ll x,ll y,ll val){
        if(x>y)return;
        update(x,val);
        update(y+1,-val);
    }
    ll lower_bound(ll sum) {// min pos st sum of [0, pos] >= sum
        // Returns n if no sum is >= sum, or -1 if sum is<=0.
        if (sum <= 0) return -1;
        ll pos = 0;
        for (ll pw = 1 << 25; pw; pw >>= 1) {
            if (pos + pw <= sz(s) && s[pos + pw-1] < sum)
                pos += pw, sum -= s[pos-1];
        }
        return pos;
    }
};

ll a[ee5];
int main()
{
    #if !ONLINE_JUDGE
 //   freopen("mx0.txt","r",stdin);
    #endif
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    ll n,m;cin>>n>>m;
    FT fenc(m+2),fenx(m+2);
    
    
    rep(i,n)cin>>a[i];     

    for(ll i=0;i<n-1;i++){
        if(a[i+1]>a[i]){
            fenc.update(a[i+1]+1,m,a[i+1]-a[i]);
            fenc.update(1,a[i],a[i+1]-a[i]);
            fenc.update(a[i]+1,a[i+1],1+a[i+1]);
            fenx.update(a[i]+1,a[i+1],-1);
        }
        else{
            fenc.update(a[i+1]+1,a[i],m-a[i]+a[i+1]);
            fenc.update(1,a[i+1],1+a[i+1]);
            fenc.update(a[i]+1,m,m+a[i+1]+1);
            fenx.update(1,a[i+1],-1);
            fenx.update(a[i]+1,m,-1);
        }
    }

    ll mini=1e15;
    for(ll i=1;i<=m;i++){        
        mini=min(mini,fenc.query(i)+i*(fenx.query(i)));
    }
    cout<<mini;
}

Measured memory_bytes: 2560