t = int(input())
for _ in range(t):
n = int(input())
a = list(map(int,input().split()))
cnt=[0]*(len(a)+1)
for x in a:
cnt[x]+=1
l = len(set(a))
m = max(cnt)
if l==m:
print(m-1)
else:
print(min(l,m))#include<bits/stdc++.h>
using namespace std;
#define fast() ios_base::sync_with_stdio(0); cin.tie(0)
#define vec vector<ll>
#define pb push_back
#define alls(s) s.begin(),s.end()
#define allv(v) v.begin(),v.end()
#define allv2(v2) v2.begin(),v2.end()
#define allrs(s) s.rbegin(),s.rend()
#define allrv(v) v.rbegin(),v.rend()
#define allrv2(v2) v2.rbegin(),v2.rend()
#define f1(i,t) for(int i=0;i<t;i++)
#define f2(i,n) for(int i=0;i<n;i++)
#define f3(j,t) for(int j=0;j<t;j++)
#define f4(j,t) for(int j=0;j<n;j++)
#define fs1(i,s) for(int i=0;i<s.size();i++)
#define fs2(i,s2) for(int i=0;i<s2.size();i++)
typedef long long ll;
int main()
{
fast();
ll t,n;
cin>>t;
while(t--)
{
cin>>n;
vec v(n);
f2(i,n)
{
cin>>v[i];
}
map<ll,ll>mp;
vector<pair<ll,ll>>v2;
f2(i,n)
{
mp[v[i]]++;
auto g=make_pair(mp[v[i]],v[i]);
v2.pb(g);
}
sort(allrv2(v2));
sort(allv(v));
auto h=unique(allv(v));
v.erase(h,v.end());
ll kk=v.size();
cout<<max(min(kk-1,v2[0].first),min(kk,v2[0].first-1))<<endl;
}
}48A - Rock-paper-scissors | 294A - Shaass and Oskols |
1213A - Chips Moving | 490A - Team Olympiad |
233A - Perfect Permutation | 1360A - Minimal Square |
467A - George and Accommodation | 893C - Rumor |
227B - Effective Approach | 1534B - Histogram Ugliness |
1611B - Team Composition Programmers and Mathematicians | 110A - Nearly Lucky Number |
1220B - Multiplication Table | 1644A - Doors and Keys |
1644B - Anti-Fibonacci Permutation | 1610A - Anti Light's Cell Guessing |
349B - Color the Fence | 144A - Arrival of the General |
1106A - Lunar New Year and Cross Counting | 58A - Chat room |
230A - Dragons | 200B - Drinks |
13A - Numbers | 129A - Cookies |
1367B - Even Array | 136A - Presents |
1450A - Avoid Trygub | 327A - Flipping Game |
411A - Password Check | 1520C - Not Adjacent Matrix |