#include <bits/stdc++.h>
using namespace std;
#define FOR for(int i=1;i<=n;i++)
#define FOr for(int i=n;i>=1;i--)
#define pb push_back
#define mp make_pair
#define sf scanf
#define pf printf
#define lo long long
#define lim 999999999
#define LIM -999999999
#define li 100005
int n,m,cev;
map<string,int> mpp;
string s;
vector<string> v;
string ss;
int main(){
cin>>n;
for(int i=1;i<=n;i++){
cin>>s;
v.pb(s);
for(int j=0;j<(int)s.size();j++){
ss+=s[j];
mpp[ss]++;
//~ cout<<"----->>"<<mpp[ss]<<'\n';
}
ss.clear();
}
for(int i=0;i<(int)v.size();i++){
if(mpp[v[i]]>1){
cev+=mpp[v[i]]-1;
}
}
cout<<cev;
return 0;
}
