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

using Int = long long;
const char newl = '\n';

template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}
template<typename T> void drop(const T &x){cout<<x<<endl;exit(0);}
template<typename T=Int>
vector<T> read(size_t n){
  vector<T> ts(n);
  for(size_t i=0;i<n;i++) cin>>ts[i];
  return ts;
}


template<typename T,T MOD = 1000000007>
struct Mint{
  static constexpr T mod = MOD;
  T v;
  Mint():v(0){}
  Mint(signed v):v(v){}
  Mint(long long t){v=t%MOD;if(v<0) v+=MOD;}

  Mint pow(long long k){
    Mint res(1),tmp(v);
    while(k){
      if(k&1) res*=tmp;
      tmp*=tmp;
      k>>=1;
    }
    return res;
  }

  static Mint add_identity(){return Mint(0);}
  static Mint mul_identity(){return Mint(1);}

  Mint inv(){return pow(MOD-2);}

  Mint& operator+=(Mint a){v+=a.v;if(v>=MOD)v-=MOD;return *this;}
  Mint& operator-=(Mint a){v+=MOD-a.v;if(v>=MOD)v-=MOD;return *this;}
  Mint& operator*=(Mint a){v=1LL*v*a.v%MOD;return *this;}
  Mint& operator/=(Mint a){return (*this)*=a.inv();}

  Mint operator+(Mint a) const{return Mint(v)+=a;}
  Mint operator-(Mint a) const{return Mint(v)-=a;}
  Mint operator*(Mint a) const{return Mint(v)*=a;}
  Mint operator/(Mint a) const{return Mint(v)/=a;}

  Mint operator-() const{return v?Mint(MOD-v):Mint(v);}

  bool operator==(const Mint a)const{return v==a.v;}
  bool operator!=(const Mint a)const{return v!=a.v;}
  bool operator <(const Mint a)const{return v <a.v;}

  static Mint comb(long long n,Int k){
    Mint num(1),dom(1);
    for(Int i=0;i<k;i++){
      num*=Mint(n-i);
      dom*=Mint(i+1);
    }
    return num/dom;
  }
};
template<typename T,T MOD> constexpr T Mint<T, MOD>::mod;
template<typename T,T MOD>
ostream& operator<<(ostream &os,Mint<T, MOD> m){os<<m.v;return os;}


template<typename T>
class BIT{
private:
  // \sum_{j < i}  v[j]
  T sum(Int i){
    T s(0);
    for(Int x=i;x>0;x-=(x&-x))
      s+=bit[x];
    return s;
  }
public:
  Int n;
  vector<T> bit;
  BIT(Int n_):n(n_+1),bit(n+1,0){}

  // v[i] += a
  void add(Int i,T a){
    for(Int x=++i;x<=n;x+=(x&-x))
      bit[x]+=a;
  }
  // \sum_{l <= i < r} v[i]
  T query(Int l,Int r){return sum(r)-sum(l);}

  // min({x | sum(x) >= w})
  Int lower_bound(const T w){
    if(w<=0) return 0;
    T r=w;
    Int x=0,p=1;
    while(p<n) p<<=1;
    for(Int k=p;k>0;k>>=1){
      if(x+k<=n&&bit[x+k]<r){
        r-=bit[x+k];
        x+=k;
      }
    }
    x++;
    assert(sum(x-1)<w and sum(x)>=w);
    return x;
  }

  // min({x | sum(x) > w})
  Int upper_bound(T w){return lower_bound(w+1);}
};

//INSERT ABOVE HERE
signed main(){
  cin.tie(0);
  ios::sync_with_stdio(0);
  Int n,k;
  cin>>n>>k;
  auto ps=read(n);
  // for(Int &p:ps) p--;

  using M = Mint<Int, 998244353>;

  M ans=M(k*(k-1)/2)/M(2);

  BIT<M> bit(n+10),cnt(n+10);
  for(Int i=0;i<k;i++){
    Int p=ps[i];
    bit.add(p,M(1));
    cnt.add(p,M(1));
  }

  // assert(n!=k);

  M ofs{1};
  M ratio=M(k-1)/M(k);
  for(Int i=k;i<n;i++){
    ofs*=ratio;
    Int p=ps[i];
    ans+=(bit.query(0,n+10)*ofs)/M(2);
    ans+=(cnt.query(p,n+10)-bit.query(p,n+10)*ofs);
    bit.add(p,M(1)/ofs);
    cnt.add(p,M(1));
  }

  cout<<ans<<newl;
  return 0;
}
