/* #region header */
#ifdef LOCAL
    #include "/Users/takakurashokichi/Desktop/atcoder/cxx-prettyprint-master/prettyprint.hpp"
    #define debug(x) cout << x << endl
#else
    #define debug(...) 42
#endif

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
//types
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
typedef pair < ll , ll > Pl;        
typedef pair < int, int > Pi;
typedef vector<ll> vl;
typedef vector<int> vi;
typedef vector<char> vc;
template< typename T >
using mat = vector< vector< T > >;
typedef vector<vector<int>> vvi;
typedef vector<vector<long long>> vvl;
typedef vector<vector<char>> vvc;

template< int mod >
struct modint {
    int x;

    modint() : x(0) {}

    modint(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}

    modint &operator+=(const modint &p) {
        if((x += p.x) >= mod) x -= mod;
        return *this;
    }

    modint &operator-=(const modint &p) {
        if((x += mod - p.x) >= mod) x -= mod;
        return *this;
    }

    modint &operator*=(const modint &p) {
        x = (int) (1LL * x * p.x % mod);
        return *this;
    }

    modint &operator/=(const modint &p) {
        *this *= p.inverse();
        return *this;
    }

    modint operator-() const { return modint(-x); }

    modint operator+(const modint &p) const { return modint(*this) += p; }

    modint operator-(const modint &p) const { return modint(*this) -= p; }

    modint operator*(const modint &p) const { return modint(*this) *= p; }

    modint operator/(const modint &p) const { return modint(*this) /= p; }

    bool operator==(const modint &p) const { return x == p.x; }

    bool operator!=(const modint &p) const { return x != p.x; }

    modint inverse() const {
        int a = x, b = mod, u = 1, v = 0, t;
        while(b > 0) {
        t = a / b;
        swap(a -= t * b, b);
        swap(u -= t * v, v);
        }
        return modint(u);
    }

    modint pow(int64_t n) const {
        modint ret(1), mul(x);
        while(n > 0) {
        if(n & 1) ret *= mul;
        mul *= mul;
        n >>= 1;
        }
        return ret;
    }

    friend ostream &operator<<(ostream &os, const modint &p) {
        return os << p.x;
    }

    friend istream &operator>>(istream &is, modint &a) {
        int64_t t;
        is >> t;
        a = modint< mod >(t);
        return (is);
    }

    static int get_mod() { return mod; }
};
//abreviations
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define rep_(i, a_, b_, a, b, ...) for (ll i = (a), max_i = (b); i < max_i; i++)
#define rep(i, ...) rep_(i, __VA_ARGS__, __VA_ARGS__, 0, __VA_ARGS__)
#define rrep_(i, a_, b_, a, b, ...) for (ll i = (b-1), min_i = (a); i >= min_i; i--)
#define rrep(i, ...) rrep_(i, __VA_ARGS__, __VA_ARGS__, 0, __VA_ARGS__)
#define SZ(x) ((ll)(x).size())
#define pb(x) push_back(x)
#define eb(x) emplace_back(x)
#define mp make_pair
#define print(x) cout << x << endl
#define vprint(x) rep(i, x.size())cout << x[i] << ' '; cout << endl
#define vsum(x) accumulate(all(x), 0LL)
#define vmax(a) *max_element(all(a))
#define vmin(a) *min_element(all(a))
#define lb(c, x) distance((c).begin(), lower_bound(all(c), (x)))
#define ub(c, x) distance((c).begin(), upper_bound(all(c), (x)))
//functions
//gcd(0, x) fails.
ll gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }
ll lcm(ll a, ll b) { return a/gcd(a, b)*b;}
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
template< typename T >
T mypow(T x, ll n) {
    T ret = 1;
    while(n > 0) {
        if(n & 1) (ret *= x);
        (x *= x);
        n >>= 1;
    }
    return ret;
}
ll modpow(ll x, ll n, const ll mod) {
    ll ret = 1;
    while(n > 0) {
        if(n & 1) (ret *= x);
        (x *= x);
        n >>= 1;
        x%=mod;
        ret%=mod;
    }
    return ret;
}
uint64_t my_rand(void) {
    static uint64_t x = 88172645463325252ULL;
    x = x ^ (x << 13); x = x ^ (x >> 7);
    return x = x ^ (x << 17);
}
ll popcnt(ull x) { return __builtin_popcountll(x); } 
//graph template
template< typename T >
struct edge {
    int src, to;
    T cost;

    edge(int to, T cost) : src(-1), to(to), cost(cost) {}

    edge(int src, int to, T cost) : src(src), to(to), cost(cost) {}

    edge &operator=(const int &x) {
        to = x;
        return *this;
    }

    bool operator<(const edge<T> &r) const { return cost < r.cost; }
    
    operator int() const { return to; }
};
template< typename T >
using Edges = vector< edge< T > >;
template< typename T >
using WeightedGraph = vector< Edges< T > >;
using UnWeightedGraph = vector< vector< int > >;
struct Timer { 
    clock_t start_time; 
    void start() {
        start_time = clock(); 
    }
    int lap() { 
        //return x ms.
        return (clock()-start_time)*1000 / CLOCKS_PER_SEC; 
    }
};
/* #endregion*/
//constant
#define inf 1000000005
#define INF 4000000004000000000LL
#define mod 1000000007LL
#define endl '\n'
typedef modint<mod> mint;
const long double eps = 0.000001;
const long double PI  = 3.141592653589793;
//library
template< typename Monoid >
struct SegmentTree {
    using F = function< Monoid(Monoid, Monoid) >;

    int sz;
    vector< Monoid > seg;

    const F f;
    const Monoid M1;

    SegmentTree(int n, const F f, const Monoid &M1) : f(f), M1(M1) {
        sz = 1;
        while(sz < n) sz <<= 1;
        seg.assign(2 * sz, M1);
    }

    void set(int k, const Monoid &x) {
        seg[k + sz] = x;
    }

    void build() {
        for(int k = sz - 1; k > 0; k--) {
            seg[k] = f(seg[2 * k + 0], seg[2 * k + 1]);
        }
    }

    void update(int k, const Monoid &x) {
        k += sz;
        seg[k] = x;
        while(k >>= 1) {
            seg[k] = f(seg[2 * k + 0], seg[2 * k + 1]);
        }
    }

    Monoid query(int a, int b) {
        Monoid L = M1, R = M1;
        for(a += sz, b += sz; a < b; a >>= 1, b >>= 1) {
            if(a & 1) L = f(L, seg[a++]);
            if(b & 1) R = f(seg[--b], R);
        }
        return f(L, R);
    }

    Monoid operator[](const int &k) const {
        return seg[k + sz];
    }

    template< typename C >
    int find_subtree(int a, const C &check, Monoid &M, bool type) {
        while(a < sz) {
            Monoid nxt = type ? f(seg[2 * a + type], M) : f(M, seg[2 * a + type]);
            if(check(nxt)) a = 2 * a + type;
            else M = nxt, a = 2 * a + 1 - type;
        }
        return a - sz;
    }

    // check(seg[i])を満たす最小のb<=iを返す.なければ-1
    template< typename C >
    int find_first(int a, const C &check) {
        Monoid L = M1;
        if(a <= 0) {
            if(check(f(L, seg[1]))) return find_subtree(1, check, L, false);
            return -1;
        }
        int b = sz;
        for(a += sz, b += sz; a < b; a >>= 1, b >>= 1) {
            if(a & 1) {
                Monoid nxt = f(L, seg[a]);
                if(check(nxt)) return find_subtree(a, check, L, false);
                L = nxt;
                ++a;
            }
        }
        return -1;
    }

    // check(seg[i])を満たす最小のi<bを返す.なければ-1
    template< typename C >
    int find_last(int b, const C &check) {
        Monoid R = M1;
        if(b >= sz) {
            if(check(f(seg[1], R))) return find_subtree(1, check, R, true);
            return -1;
        }
        int a = sz;
        for(b += sz; a < b; a >>= 1, b >>= 1) {
            if(b & 1) {
                Monoid nxt = f(seg[--b], R);
                if(check(nxt)) return find_subtree(b, check, R, true);
                R = nxt;
            }
        }
        return -1;
    }
};
int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    cout << setprecision(20);
    ll n; cin>>n;
    vector<string> S(n);
    rep(i, n){
        cin>>S[i];
        reverse(all(S[i]));
    }
    sort(all(S));
    vl id(n);
    iota(all(id), 0);
    sort(all(id), [&](int i, int j){return S[i].size()>S[j].size();});

    auto f = [&](ll x, ll y){return x+y;};
    vector<SegmentTree<ll>> seg(26, SegmentTree<ll>(n, f, 0));

    unordered_set<ll> que;
    ll len = S[id[0]].size();
    ll ans = 0;
    for(int i:id){
        if(len>S[i].size()-1){
            for(int j:que){
                rep(k, S[i].size()-1, len)
                    seg[S[j][k]-'a'].update(j, 1);
            }
        }
        chmin(len, (ll)S[i].size()-1);
        que.insert(i);
        seg[S[i].back()-'a'].update(i, 1);
        string x = "";
        rep(j, S[i].size()-1) x+=S[i][j];
        ll l = ub(S, x);
        ll r = ub(S, x+'{');
        ans+=seg[S[i].back()-'a'].query(l, r)-1; 
    }
    print(ans);
} 


Measured memory_bytes: 125892