#include <fstream>
#include <iomanip>
#include <queue>

using namespace std;
ifstream f("dstar.in");
ofstream g("dstar.out");
int r,p,i,n;
double u,s,x;
priority_queue<double> v;
int main()
{
    f>>r>>p;
    for(i=1;i<=r;i++)
    {
        f>>u;
        s+=u;
        v.push(u);
    }
    v.push(360-s);
    for(i=1;i<=p;i++)
    {
        x=v.top();
        v.pop();
        v.push(x/2);
        v.push(x/2);
    }
    x=v.top();
    g<<fixed<<setprecision(6)<<x;
    return 0;
}