#include <iostream>
#include <vector>
using namespace std;
int Bits(int number)
{
int n = 0;
while (number != 0)
{
if (number & 1)
{
n++;
}
number >>= 1;
}
return n;
}
vector<long long> song;
int songLength;
long long maxPower;
long long Solve(int currentSecond, long long minPower, long long value, int stage)
{
if (currentSecond >= songLength)
{
return value;
}
long long max = -1, t;
for (long long i = minPower; i <= maxPower; i++)
{
long long v = value + (Bits(i) * song[currentSecond]);
t = Solve(currentSecond + 1, i + 1, v, stage + 1);
if (t > max)
{
max = t;
}
}
return max;
}
int main()
{
long long temp;
cin >> songLength >> maxPower;
for (int i = 0; i < songLength; i++)
{
cin >> temp;
song.push_back(temp);
}
cout << Solve(0, 0, 0, 0) << endl;
return 0;
}