//RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM
#include <bits/stdc++.h>
using namespace std;
using ll=long long;
int main() {
// your code goes here
int n;
cin>>n;
vector<ll>arr(n);
for(ll i=0;i<n;i++) cin>>arr[i];
unordered_map<int,int>mp;
for(ll i=0;i<n;i++){
mp[arr[i]]++;
}
ll ans=0;
for(auto x:mp){
ll y=x.second;
ll t=y%3;
ll s=y/3;
ll curr=0;
if(t==1){
curr=2;
curr+=(s-1>=0)?s-1:0;
}
else if(t==2) {
curr=1+s;
}
else curr=s;
ans+=curr;
}
cout<<ans<<endl;
return 0;
}
//RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM RAM
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