#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;
long long n,m;
long long N;
long long jyx[300],a[30000],yx[200],maxx=-1;
int print()
{
    memset(a,0,sizeof(a));
    long long s=0,ans=0;
    for(int i=1;i<=N;++i)
    {
      s=0;
      for(int j=0;j<=n-m-1;++j)
      if(i&(1<<j))s+=yx[j+1]; 
      if(s!=0)a[s]++;
      if(a[s]==1)ans++; 
    }
    maxx=max(maxx,ans);
}
int locin(int k,int b)
{
    for(int i=b;i<=m+k;++i)
     {
         yx[k]=jyx[i];
         if(k==n-m)print();
         else locin(k+1,i+1);
     }
}
int main()
{
    cin>>n>>m;
    N=1<<(n-m);
    for(int i=1;i<=n;++i)cin>>jyx[i];
    locin(1,1);
    cout<<maxx;
    return 0;
}