1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
#include <cstdio>
#include <cmath>
#include <iostream>
#include <algorithm>
#include <queue>
#include <list>
#include <vector>
#include <map>
#include <set>
#include <string>
#include <cstring>
#include <cassert>
#include <limits.h>

using namespace std;

#define ST first
#define ND second
#define MP make_pair
#define PB push_back

typedef long long LL;
typedef long double LD;

typedef vector<int> VI;
typedef pair<int,int> PII;
#define REP(i,n) for(int i=0;i<(n);i++)
#define FOR(i,a,b) for(VAR(i,a);i<=(b);++i)
#define FORD(i,a,b) for(VAR(i,a);i>=(b);--i)
#define FORE(a,b) for(VAR(a,(b).begin());a!=(b).end();++a)
#define VAR(a,b) __typeof(b) a=(b)
#define SIZE(a) ((int)((a).size()))
#define ALL(x) (x).begin(),(x).end()
#define CLR(x,a) memset(x,a,sizeof(x))
#define ZERO(x) memset(x,0,sizeof(x))
#define S(t,i) scanf("%" ## t, &i)
#define SI(i) scanf("%d", &i)

const int MAXN=200+5;
long long int a[MAXN];
int n;
long long int m, result=-1000000000000000;

int countBits(unsigned long long int v) {
    int c = 0; // c accumulates the total bits set in v
    for (; v; c++)
    {
        v &= v - 1; // clear the least significant bit set
    }
    return c;
}

void eval(int i, long long int b, long long int r) {
    if (b > m) {
        return;
    } else {
        int bitsSet = countBits(b);
        r += bitsSet * a[i];
        if (i+1 == n) {
            if (r > result) {
                result = r;
            }
        } else {
            eval(i+1, b+1, r);
            
            if (a[i+1] > 0) {
                long long int p2 = 1;
                while (b < m) {
                    if ((b & p2) == 0) {
                        b |= p2;
                        eval(i+1, b, r);
                    }
                    p2 <<= 1;
                }
            } else if (a[i+1] < 0 && b > 0) {
                while (b < m) {
                    long long int p2 = b - (b & (b - 1));
                    if (b == p2) {
                        break;
                    }
                    b += p2;
                    eval(i+1, b, r);
                }
            }
        }
    }
}


int main() {
    ios_base::sync_with_stdio(0);
    
    cin >> n;
    cin >> m;
    
    REP(i, n) {
        cin >> a[i];
    }
    
    eval(0, 0, 0);
    
    long long int b = 0;
    long long int r = 0;
    
    if (a[0] > 0) {
        long long int p2 = 1;
        while (b < m) {
            if ((b & p2) == 0) {
                b |= p2;
//                 cout << b << "\n";
                eval(0, b, r);
            }
            p2 <<= 1;
        }
    }
    
    cout << result;
    return 0;
}