#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const long long mod=19260817;
long long nn,x,a,maxx=0;
long long cnt[1550]={0},p[1550],ex[1550];
long long f[1550]={0};
bool ok[1550];
long long C(long long n,long long m)
{
    if(n<m) return 0;
    if(n==m) return 1;
    if(m==1) return n%mod;
    long long c=1;
    for(long long i=1;i<=m;i++)
        c=(c*(n-i+1)/i)%mod;
    return c;
}
long long cal(long long i)
{
    if(ex[i]) return ex[i];//memorizing search
    memset(p,0,sizeof(p));
    long long an=0;
    for(long long j=1;j<=min(maxx,i);j++)
    {
        if(p[j]) return an;//avoid repeated calculating
        if(j!=i-j)
        {
            an=(an+cnt[j]*cnt[i-j])%mod;
            p[j]=p[i-j]=1;
        }
        else
        {
            an=(an+C(cnt[j],2))%mod;
            p[j]=1;
        }
    }
    return ex[i]=an;
}

int main()
{
//    freopen("ft.in","r",stdin);
//    freopen("ft.out","w",stdout);
    cin>>nn>>x;
    for(int i=1;i<=nn;i++)
    {
        cin>>a;
        maxx=max(maxx,a);
        cnt[a]++;
        if(cnt[a]>=x-2)
            ok[a]=1;
    }
    for(int i=1;i<=maxx;i++)
    {
        if(ok[i])//if it is possible for this edge to be the longest edge
        {
            long long a1=C(cnt[i],x-2);
            long long a2=cal(i);
            f[i]=(a1*a2)%mod;
            //pick x-2 out of cnt[i] for the longest edge
            //how many couple can make up i
            //multiply both above
        }
    }
    long long ans=0;
    for(long long i=1;i<=maxx;i++)
        ans=(ans+f[i])%mod;
    cout<<ans;
    return 0;
}