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#include <bits/stdc++.h>

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define FORD(i, a, b) for(int i = (a); i >= (b); --i)
#define VAR(v, i) __typeof(i) v=(i)
#define FORE(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i)
#define all(v) (v).begin(),(v).end()

#define PII pair<int,int>
#define st first
#define nd second
#define pb push_back
#define lint long long int
#define VI vector<int>

#define debug(x) {cout <<#x <<" = " <<x <<endl; }
#define debug2(x,y) {cerr <<#x <<" = " <<x << ", "<<#y<<" = "<< y <<endl; } 
#define debug3(x,y,z) {cerr <<#x <<" = " <<x << ", "<<#y<<" = "<< y << ", " << #z << " = " << z <<endl; } 
#define debugv(x) {{cout <<#x <<" = "; FORE(itt, (x)) cerr <<*itt <<", "; cerr <<endl; }}
#define debugt(t,n) {{cerr <<#t <<" = "; FOR(it,0,(n)) cerr <<t[it] <<", "; cerr <<endl; }}

#define make( x) int (x); scanf("%d",&(x));
#define make2( x, y) int (x), (y); scanf("%d%d",&(x),&(y));
#define make3(x, y, z) int (x), (y), (z); scanf("%d%d%d",&(x),&(y),&(z));
#define make4(x, y, z, t) int (x), (y), (z), (t); scanf("%d%d%d%d",&(x),&(y),&(z),&(t));
#define makev(v,n) VI (v); FOR(i,0,(n)) { make(a); (v).pb(a);} 
#define IOS ios_base::sync_with_stdio(0)
#define HEAP priority_queue

#define read( x) scanf("%d",&(x));
#define read2( x, y) scanf("%d%d",&(x),&(y));
#define read3(x, y, z) scanf("%d%d%d",&(x),&(y),&(z));
#define read4(x, y, z, t) scanf("%d%d%d%d",&(x),&(y),&(z),&(t));
#define readv(v,n) FOR(i,0,(n)) { make(a); (v).pb(a);}
#define jeb() fflush(stdout);

using namespace std;

int n;
lint m;
vector<lint> v;
lint pref[205];
lint dp[205][205][62];
lint dp2[205][62];

lint INF = 1e9*1LL*1e9;

lint sum(int i, int j) {
	if (i > j) return 0;
	return pref[j] - ((i==0)? 0 : pref[i-1]);
}

// odpowiedz dla przedzialu [i,j) 
// z wagami [0,2^k-1]
lint rob(int i, int j, int k) {
	if (dp[i][j][k] != -INF-1) return dp[i][j][k];
	if (i == j) return 0;
	if (j-i > (1LL<<k)) return -INF;
	if (k == 0) return 0; 
	lint best = -INF;
	FOR(s,i,j+1) {
		best = max(best, sum(s,j-1) + rob(i,s,k-1) + rob(s,j,k-1));
	}
	dp[i][j][k] = best;
	return best;
}

// odpowiedz dla przedzialu [i, n)
// z wagami [0,m&(2^k-1)]
lint rob2(int i, int k) {
	if (dp2[i][k] != -INF -1) return dp2[i][k];
	if (i == n) return 0;
	lint up = m & ((1LL<<k) - 1);
	if (up+1 < n-i) return -INF;
	if (up == 0) return 0;
	if ((m & (1LL<<(k-1))) == 0) {
		return rob2(i, k-1);
	}
	lint best = -INF;
	FOR(s,i,n+1) {
		best = max(best, sum(s,n-1) + rob(i,s,k-1) + rob2(s,k-1));
	}
	dp2[i][k] = best;
	return best;
}

void brut() {
	int u = 60;
	while (u > 0 && (1LL<<u) > m) u--;
	u++;
	FOR(i,0,n+1) FOR(j,i,n+1) FOR(k,0,61) dp[i][j][k] = -INF-1;
	FOR(i,0,n+1) FOR(k,0,61) dp2[i][k] = -INF-1;
	printf("%lld\n", rob2(0,u));
}

int main() {
	read(n);
	scanf("%lld", &m);
	FOR(i,0,n) {
		lint a; scanf("%lld", &a);
		v.pb(a);
	}
	pref[0] = v[0];
	FOR(i,1,n) pref[i] = pref[i-1] + v[i];
	brut();
}