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#include <bits/stdc++.h>
#define FOR(i, n) for(int i = 0; i < (n); ++i)
#define REP(i, a, b) for(int i = (a); i < (b); ++i)
#define TRAV(i, n) for(auto &i : n)
#define SZ(x) (int)(x).size()
#define PR std::pair
#define MP std::make_pair
#define X first
#define Y second
typedef long long ll;
typedef std::pair<int, int> PII;
typedef std::vector<int> VI;

const ll INF = 3ll*1000000000ll*1000000000ll;
int n;
ll A[205], dp[205][205][130];
PII lp[130];
int fre;
std::unordered_map<ll, int> map;

int xdrec(ll a){
	if(map.count(a)) return map[a];
	map[a] = fre++;
	int xd = 63-__builtin_clzll(a);
	ll big = 1ll<<xd;
	lp[map[a]].X = xdrec(big-1);
	lp[map[a]].Y = xdrec(a-big);
	return map[a];
}

ll rec(int l, int r, int val){
	if(val == 0) return l == r ? 0ll : -INF;
	if(dp[l][r][val] != INF) return dp[l][r][val];
	ll best = rec(l, r, lp[val].X);
	ll add = 0;
	for(int m = r; m > l; --m){
		add += A[m];
		ll cand = rec(l, m-1, lp[val].X)+add+rec(m, r, lp[val].Y);
		best = std::max(cand, best);
	}
	add += A[l];
	best = std::max(best, add+rec(l, r, lp[val].Y));
	return dp[l][r][val] = best;
}

int main(){
	std::ios_base::sync_with_stdio(false);
	std::cin.tie(0);
	ll m;
	std::cin >> n >> m;
	FOR(i, n) std::cin >> A[i+1];
	map[0] = 0;
	fre = 1;
	xdrec(m);
	FOR(i, n+1) FOR(j, n+1) FOR(a, fre) dp[i][j][a] = INF;
	std::cout << rec(1, n, map[m]);
	return 0;
}