#include
using namespace std;
int main(){
int t=0;
cin>>t;
be:
while(t--){
int n=0,a[32]={0},s=0;
cin>>n;
for(int i=0;i>a[i];
if(n==1) cout<<"0\n";
else{
for(int i=n-2;i>=0;i--){
if(a[i]==0&&i!=0||a[i+1]==0){
cout<<"-1\n";
goto be;
}
while(a[i]>=a[i+1]){
a[i]/=2;
s++;
}
}
cout<