int main()
{
    double sum;
    int m,n,k,i;
    cin>>m;                         //???????? 
    for (i=1;i<=m;i++)
        {
         sum=0;
         cin>>n;                    //???n? 
         float a[n],b[n];
         a[0]=2;                    
         a[1]=3;                    //??a[n]??????? 
         b[0]=1;
         b[1]=2;                    //??b[n]??????? 
         for (k=2;k<n;k++)
             {
              a[k]=a[k-1]+a[k-2];   //??a[n]?? 
              b[k]=b[k-1]+b[k-2];   //??b[n]?? 
             }
         for (k=0;k<n;k++)
             sum=sum+a[k]/b[k];
         printf ("%.3f",sum);       //?????? 
         printf ("\n");
        }
    return 0;
}
