#include <bits/stdc++.h>

using namespace std;
typedef long long LL;
typedef pair<int,int> pii;

#define pb push_back
#define eb emplace_back
#define mp make_pair
#define fi first
#define se second

void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}

#ifdef OJ
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

#define all(x) (x).begin(), (x).end()
#define rsort(x) sort((x).rbegin(), (x).rend())
#define sz(x) ((int)x.size())
#define fori(i, n) for (int i = 0; i < (int)(n); ++i)
#define ford(i, n, e) for (int i = (int)(n); i >= (int)(e); --i)
#define fore(i, a, b) for (int i = (int)(a); i <= (int)(b); ++i)
template<typename T> bool mmax(T &m, const T q) { if (m < q) {m = q; return true;} else return false; }
template<typename T> bool mmin(T &m, const T q) { if (m > q) {m = q; return true;} else return false; }
#define RETURN(x) do{cout << (x) << '\n'; return 0;}while(0)

const char en = '\n';
const int MOD = 0;
const int MAXN = 0;
const int INF = 1e9;

struct stNode {
    vector<stNode*> child = vector<stNode*>(26, NULL);
    vector<int> has = vector<int>(26);

    void add(const string &s, const vector<int> &lst, int i) {
        if(i == sz(s)) return;
        int c = s[i]-'a';
        if(child[c] == NULL) child[c] = new stNode();
        fori(k,26) {
            if(lst[k] >= i) { 
                has[k]++;
            }
        }
        child[c]->add(s,lst,i+1);
    }

    int check(const string& s, int i) {
        int c = s[i]-'a';
        if(i == sz(s)-1) {
            return has[c];
        }
        if(child[c] == NULL) return false;
        return child[c]->check(s,i+1);
    }
};

int solve() {
    int n; cin >> n;
    vector<string> v(n);
    map<string,int> m;
    fori(i,n) {
        cin >> v[i];
        reverse(all(v[i]));
        m[v[i]]++;
    }

    stNode *root1 = new stNode();
    LL ans = 0;
    fori(i,n) {
        string &s = v[i];
        ans += root1->check(s,0);

        debug(s,ans);

        vector<int> lst(26,-1);
        fori(j,sz(s)) lst[s[j]-'a'] = j;

        root1->add(s,lst,0);
    }

    stNode *root2 = new stNode();
    ford(i,n-1,0) {
        string &s = v[i];
        ans += root2->check(s,0);

        vector<int> lst(26,-1);
        fori(j,sz(s)) lst[s[j]-'a'] = j;

        root2->add(s,lst,0);
    }

    for(auto &it: m) {
        ans -= 1LL*it.se*(it.se-1)/2;
    }
    cout << ans << en;
    return 0;
} 

int main(int argc, char **argv) {
#ifdef OJ
    freopen("input.txt", "rt", stdin);
    //freopen("output.txt", "wt", stdout);
#endif
    ios::sync_with_stdio(false);
    cin.tie(0);

    int ntest = 1;
    //cin >> ntest;
    fori(test, ntest) {
        //cout << "Case #" << test+1 << ": ";
        solve();
    }

    return 0;
    }



Measured memory_bytes: 785740