#include<bits/stdc++.h>
using namespace std;
int main(){
	int n, k; cin >> n >> k;
	vector<int> w_og(n); for(int& x : w_og) cin >> x;
	int ans=0;
	for(int bm=0;bm<(1<<n);bm++){
		//printf("{%X %x}", bm, 0b1010);
		vector<array<int, 3>> pq;
		vector<bool> eaten(n, false);
		for(int i=0;i<n;i++){
			for(int j=i+1;j<n;j++){
				int dirI=(bm>>i)&1, dirJ=(bm>>j)&1;
				if(dirI==1 && dirJ==0) pq.push_back({j-i, i, j});
				if(dirI==1 && dirJ==1) pq.push_back({2*(n-j)+j-i, i, j});
				if(dirI==0 && dirJ==0) pq.push_back({2*(i+1)+j-i, i, j});
				if(dirI==0 && dirJ==1) pq.push_back({2*(n+1)+j-i, i, j});
			}
		}
		sort(pq.begin(), pq.end());
		vector<int> w=w_og;
		for(auto [x, a, b] : pq){
			if(!eaten[a] && !eaten[b]){
				//printf("[%d %d %d]", x, a, b);
				if(w[a]<w[b]){
					eaten[a]=true;
					w[b]+=w[a];
				}
				else if(w[b]<w[a]){
					eaten[b]=true;
					w[a]+=w[b];
				}
				else if(a<b){
					eaten[a]=true;
					w[b]+=w[a];
				}
				else{
					eaten[b]=true;
					w[a]+=w[b];
				}
			}
		}
		//printf("\n");
		ans+=!eaten[k-1];
	}
	printf("%d", ans);
	return 0;
}