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;
}
}237. Delete Node in a Linked List | 27. Remove Element |
39. Combination Sum | 378. Kth Smallest Element in a Sorted Matrix |
162. Find Peak Element | 1529A - Eshag Loves Big Arrays |
19. Remove Nth Node From End of List | 925. Long Pressed Name |
1051. Height Checker | 695. Max Area of Island |
402. Remove K Digits | 97. Interleaving String |
543. Diameter of Binary Tree | 124. Binary Tree Maximum Path Sum |
1465. Maximum Area of a Piece of Cake After Horizontal and Vertical Cuts | 501A - Contest |
160A- Twins | 752. Open the Lock |
1535A - Fair Playoff | 1538F - Interesting Function |
1920. Build Array from Permutation | 494. Target Sum |
797. All Paths From Source to Target | 1547B - Alphabetical Strings |
1550A - Find The Array | 118B - Present from Lena |
27A - Next Test | 785. Is Graph Bipartite |
90. Subsets II | 1560A - Dislike of Threes |