#include<bits/stdc++.h>

using namespace std;

typedef long long ll;

typedef priority_queue<int, vector<int>, greater<int>> pqmin;

#define endl '\n'

#define pb push_back

#define all(x) (x).begin(), (x).end()

#define rall(x) (x).rbegin(), (x).rend()

#define fi first

#define se second

#define fr(i,n) for(int i=0;i<n;i++)

#define pyes cout<<"YES\n"

#define pno cout<<"NO\n"

typedef pair<int,int> pii;

typedef pair<ll,ll> pll;

typedef vector<int> vi;

typedef vector<ll> vll;

typedef vector<pll> vpll;

typedef vector<pii> vpii;

const int MOD = 1e9+7;

#ifndef ONLINE_JUDGE

#define debug(x) cerr << #x << " = "; _print(x); cerr << endl;

#else

#define debug(x)

#endif

void _print(int t) {cerr << t;}

void _print(string t) {cerr << t;}

void _print(char t) {cerr << t;}

void _print(long double t) {cerr << t;}

void _print(double t) {cerr << t;}

void _print(unsigned long long t) {cerr << t;}

template <class T, class V> void _print(pair<T, V> p);

template <class T> void _print(vector<T> v);

template <class T> void _print(set<T> v);

template <class T, class V> void _print(map<T, V> v);

template <class T> void _print(multiset<T> v);

template <class T, class V> void _print(pair<T, V> p) {cerr << "{"; _print(p.first); cerr << ","; _print(p.second); cerr << "}";}

template <class T> void _print(vector<T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}

template <class T> void _print(set<T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}

template <class T> void _print(multiset<T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}

template <class T, class V> void _print(map<T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}

int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }

int lcm(int a, int b) { return (a / gcd(a, b)) * b; }

int modpow(int a, int b, int mod = MOD) {

int res = 1;

while (b) {

if (b & 1) res = (res * a) % mod;

a = (a * a) % mod;

b >>= 1;

}

return res;

}

struct Matrix {

ll a[2][2];

};

Matrix multiply(Matrix A, Matrix B) {

Matrix C;

C.a[0][0] = (A.a[0][0]*B.a[0][0] + A.a[0][1]*B.a[1][0]) % MOD;

C.a[0][1] = (A.a[0][0]*B.a[0][1] + A.a[0][1]*B.a[1][1]) % MOD;

C.a[1][0] = (A.a[1][0]*B.a[0][0] + A.a[1][1]*B.a[1][0]) % MOD;

C.a[1][1] = (A.a[1][0]*B.a[0][1] + A.a[1][1]*B.a[1][1]) % MOD;

return C;

}

Matrix power(Matrix M, ll n) {

Matrix R = {{{1, 0}, {0, 1}}}; // identity

while(n){

if(n & 1) R = multiply(R, M);

M = multiply(M, M);

n >>= 1;

}

return R;

}

vector<int> sieve(int n) {

vector<int> isPrime(n + 1, 1);

isPrime[0] = isPrime[1] = 0;

for (int i = 2; i*i <= n; i++)

if (isPrime[i])

for (int j = i*i; j <= n; j += i)

isPrime[j] = 0;

return isPrime;

}

bool isPrime(int n) {

if (n <= 1) return false;

if (n <= 3) return true;

if (n % 2 == 0 || n % 3 == 0) return false;

for (int i = 5; i * i <= n; i += 6) {

if (n % i == 0 || n % (i + 2) == 0)

return false;

}

return true;

}

void solve() {

int n;

cin>>n;

set<int> s;

for(int i=0;i<n;i++){

int ele;

cin>>ele;

s.insert(ele);

}

cout<<s.size()<<endl;

}

int main() {

ios::sync_with_stdio(0);

cin.tie(0);

int t = 1;

cin >> t;

while (t--) {

solve();

}

return 0;

}