double avg = 0;
int n = 0;

for(int i = 0; i < arr.length; i++)
{
    int x = arr[i];

    if (Math.abs(x) % 2 == 1)
    {
        n++;
        avg += x;
    }
}

if (n != 0)
    System.out.printf("%.2f", avg / n);
else
    System.out.println("NO");