#include <bits/stdc++.h>
#ifndef LOCAL
#include "biscuits.h"
#endif
using namespace std;
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define Time (clock() * 1.0 / CLOCKS_PER_SEC)
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using ld = long double;
template<typename T1, typename T2> bool chkmin(T1& x, T2 y) {
return y < x ? (x = y, true) : false;
}
template<typename T1, typename T2> bool chkmax(T1& x, T2 y) {
return y > x ? (x = y, true) : false;
}
void debug_out() {
cerr << endl;
}
template<typename T1, typename... T2> void debug_out(T1 A, T2... B) {
cerr << ' ' << A;
debug_out(B...);
}
template<typename T> void mdebug_out(T* a, int n) {
for (int i = 0; i < n; ++i)
cerr << a[i] << ' ';
cerr << endl;
}
#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define mdebug(a, n) cerr << #a << ": ", mdebug_out(a, n)
#else
#define debug(...) 1337
#define mdebug(a, n) 1337
#endif
template<typename T> ostream& operator << (ostream& stream, const vector<T>& v) {
for (auto& e : v)
stream << e << ' ';
return stream;
}
template<typename T1, typename T2> ostream& operator << (ostream& stream, const pair<T1, T2>& p) {
return stream << p.first << ' ' << p.second;
}
const ll INF64 = 1e18;
ll count_tastiness(ll x, vector<ll> a) {
int k = a.size();
if (*max_element(all(a)) == 0) return 1;
assert(x == 1);
vector<ll> f(k, 0);
vector<ll> extra(k, 0);
int j = 0;
while (!a[j]) ++j;
f[j] = a[j] + 1;
extra[j] = 1;
for (int i = j + 1; i < k; ++i) {
if (a[i] == 0) {
f[i] = f[i - 1];
continue;
}
ll c = (1ll << (i - j));
if (a[j] + 1 > c) {
ll p = (f[j] - extra[j]) / a[j];
ll t = p * c;
extra[i] = extra[j] + p * (a[j] - c);
f[i] = t * (a[i] + 1) + extra[i];
} else {
ll t = f[j];
f[i] = t * (a[i] + 1);
extra[i] = t;
}
}
return f.back();
}
#ifdef LOCAL
mt19937 rng(228);
ll randll(ll L, ll R) {
return rng() % (R - L + 1) + L;
}
int32_t main() {
#ifdef LOCAL
freopen("in", "r", stdin);
#endif
ios::sync_with_stdio(0);
cin.tie(0);
/*const ll C = 4;
for (int test = 1; ; ++test) {
ll x = 1;
int k = 2;
vector<ll> a(k);
for (auto& x : a)
x = randll(0, C);
if (count_tastiness(x, a) != count_tastiness_stu(x, a)) {
cout << "1\n";
cout << x << ' ' << k << '\n';
cout << a << '\n';
exit(0);
}
if (test % 1000 == 0) debug(test);
}/**/
int q;
assert(scanf("%d", &q) == 1);
vector<int> k(q);
vector<long long> x(q);
vector<vector<long long>> a(q);
vector<long long> results(q);
for (int t = 0; t < q; t++) {
assert(scanf("%d%lld", &k[t], &x[t]) == 2);
a[t] = vector<long long>(k[t]);
for (int i = 0; i < k[t]; i++) {
assert(scanf("%lld", &a[t][i]) == 1);
}
}
fclose(stdin);
for (int t = 0; t < q; t++) {
results[t] = count_tastiness(x[t], a[t]);
}
for (int t = 0; t < q; t++) {
printf("%lld\n", results[t]);
}
fclose(stdout);
return 0;
}
#endif
