#include <bits/stdc++.h>
using namespace std;
#define LOCAL
#pragma region Macros
typedef long long ll;
#define ALL(x) (x).begin(),(x).end()
const long long MOD=1000000007;
// const long long MOD=998244353;
const int INF=1e9;
const long long IINF=1e18;
const int dx[4]={1,0,-1,0},dy[4]={0,1,0,-1};
const char dir[4]={'D','R','U','L'};

template<typename T>
istream &operator>>(istream &is,vector<T> &v){
    for (T &x:v) is >> x;
    return is;
}
template<typename T>
ostream &operator<<(ostream &os,const vector<T> &v){
    for (int i=0;i<v.size();++i){
        os << v[i] << (i+1==v.size()?"": " ");
    }
    return os;
}
template<typename T,typename U>
ostream &operator<<(ostream &os,const pair<T,U> &p){
    os << '(' << p.first << ',' << p.second << ')';
    return os;
}
template<typename T,typename U>
ostream &operator<<(ostream &os,const map<T,U> &m){
    os << '{';
    for (auto itr=m.begin();itr!=m.end();++itr){
        os << '(' << itr->first << ',' << itr->second << ')';
        if (++itr!=m.end()) os << ',';
        --itr;
    }
    os << '}';
    return os;
}
template<typename T>
ostream &operator<<(ostream &os,const set<T> &s){
    os << '{';
    for (auto itr=s.begin();itr!=s.end();++itr){
        os << *itr;
        if (++itr!=s.end()) os << ',';
        --itr;
    }
    os << '}';
    return os;
}

void debug_out(){cerr << '\n';}
template<class Head,class... Tail>
void debug_out(Head&& head,Tail&&... tail){
    cerr << head;
    if (sizeof...(Tail)>0) cerr << ", ";
    debug_out(move(tail)...);
}
#ifdef LOCAL
#define debug(...) cerr << " ";\
cerr << #__VA_ARGS__ << " :[" << __LINE__ << ":" << __FUNCTION__ << "]" << '\n';\
cerr << " ";\
debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

template<typename T> T gcd(T x,T y){return y!=0?gcd(y,x%y):x;}
template<typename T> T lcm(T x,T y){return x/gcd(x,y)*y;}

template<class T1,class T2> inline bool chmin(T1 &a,T2 b){
    if (a>b){a=b; return true;} return false;
}
template<class T1,class T2> inline bool chmax(T1 &a,T2 b){
    if (a<b){a=b; return true;} return false;
}
#pragma endregion

template<int char_size>
struct Trie{
    struct TrieNode{
        char c; int dep;
        vector<int> nxt,idxs;
        TrieNode(char c,int dep):c(c),dep(dep),nxt(char_size,-1){}
    };
    vector<TrieNode> Nodes;
    function<int(char)> ctoi;
    Trie(function<int(char)> ctoi):ctoi(ctoi){
        Nodes.emplace_back('$',0);
    }
    inline int &next(int node,int c){
        return Nodes[node].nxt[c];
    }
    inline int &next(int node,char c){
        return next(node,ctoi(c));
    }
    void add(const string &s,int x=0){
        int node=0;
        for (int i=0;i<s.size();++i){
            int k=ctoi(s[i]);
            if (next(node,k)<0){
                next(node,k)=Nodes.size();
                Nodes.emplace_back(s[i],i+1);
            }
            node=next(node,k);
        }
        Nodes[node].idxs.emplace_back(x);
    }
    int find(const string &s){
        int node=0;
        for (int i=0;i<s.size();++i){
            int k=ctoi(s[i]);
            if (next(node,k)<0) return -1;
            node=next(node,k);
        }
        return node;
    }
    template<typename F>
    void query(const string &s,const F &f,int l){
        int node=0;
        for (int i=l;i<s.size();++i){
            node=next(node,s[i]);
            if (node<0) return;
            for (auto &idx:Nodes[node].idxs) f(idx);
        }
    }
    int size(){return Nodes.size();};
    vector<int> idxs(int node){return Nodes[node].idxs;}
};

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N; cin >> N;
    vector<string> S(N); cin >> S;

    sort(S.begin(),S.end(),[](string a,string b){return a.size()<b.size();});
    ll ans=0;
    auto ctoi=[](char c){return c-'a';};
    Trie<26> trie(ctoi);

    for (int i=0;i<N;++i){
        reverse(S[i].begin(),S[i].end());
        vector<int> cnt(26,0);
        int n=S[i].size();
        for (int j=0;j<n;++j) ++cnt[ctoi(S[i][j])];
        int now=0;
        for (int j=0;j<n;++j){
            for (int k=0;k<26;++k){
                if (cnt[k]>0){
                    int nxt=trie.Nodes[now].nxt[k];
                    if (nxt<0) continue;
                    ans+=trie.idxs(nxt).size();
                }
            }
            now=trie.Nodes[now].nxt[ctoi(S[i][j])];
            if (now<0) break;
            --cnt[ctoi(S[i][j])];
        }
        trie.add(S[i]);
    }

    cout << ans << '\n';
}

Measured memory_bytes: 167992