#include<bits/stdc++.h>
using namespace std;
int main()
{ios_base::sync_with_stdio(false);
cin.tie(NULL);
    long long q;
cin>>q;
while(q--)
{long long n,sm=0;
cin>>n;
vector<long long>v;
long long a[n+1];
memset(a,0,sizeof(a));
for(int i=0;i<n;i++)
{int x;
	cin>>x;
a[x]++;    
}
for(int i=0;i<n+1;i++)
{v.push_back(a[i]);
}sort(v.begin(),v.end());
long long cnt=0;
for(auto it=v.end()-1;it!=v.begin()-1;it--)
{
*it-cnt;
if(*it-cnt>0)
	sm=sm+*it-cnt;
cnt++;
}
cout<<sm;
v.clear();
cout<<"\n";    
}
}

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Mwo4CjEgNCA4IDQgNSA2IDMgOAoxNgoyIDEgMyAzIDQgMyA0IDQgMSAzIDIgMiAyIDQgMSAxCjkKMiAyIDQgNCA0IDcgNyA3IDcK

3
8
1 4 8 4 5 6 3 8
16
2 1 3 3 4 3 4 4 1 3 2 2 2 4 1 1
9
2 2 4 4 4 7 7 7 7