#include<bits/stdc++.h> using namespace std; #define ll long long #define ul unsigned long long #define pb push_back #define ss second #define ff first #define fr(m) for(int i=0; i<m; i++) #define fro(m) for(int i=1; i<m; i++) #define frj(m) for(int j=0; j<m; j++) #define frr(n) for(int i=n; i>=0; i--) #define nl '\n' #define yes cout<<"YES"<<nl #define no cout<<"NO"<<nl #define all(x) x.begin(), x.end() #define dbg(x) cerr << #x <<" "<< x << endl; #define fast_io (ios_base:: sync_with_stdio(false),cin.tie(NULL)); ll fact(ll n){ if(n==0) return 1; ll res = 1; for (ll i = 2; i <= n; i++) res = res * i; return res;} ll nPr(ll n, ll r) { return fact(n) / fact(n - r); } ll nCr(ll n, ll r) { return fact(n) / (fact(r) * fact(n - r)); } ll gcd(ll a, ll b) { if (b == 0) return a; return gcd(b, a % b); } ll lcm(ll a, ll b) { return (a * b) / gcd(a, b);} ll mypow(ll a, ll b){ ll ans = 1; while(b){ if (b&1) ans = (ans*a) ; b /= 2; a = (a*a); } return ans; } bool isPrime(ll n) { if(n <= 1) return false; for(ll i = 2; i <= sqrt(n); i++) if(n % i == 0) return false; return true;} #define PI 3.141592653589793238; #define INF LONG_LONG_MAX; #define MOD 1e9+7; //////////////////////////////////Code Start///////////////////////////////////// void solve() { ll n; cin>>n; ll ct1=0, ct0=0; fr(n) { int x; cin>>x; if(x==1) ct1++; else if(x==0) ct0++; } if(ct1!=0) { ll ans; if(ct0==0) ans=ct1; else ans=ct1*pow(2,ct0); cout<<ans<<nl; } else cout<<0<<nl; } int main() { fast_io; int TC = 1; cin >> TC; while (TC--) solve(); }