/*  author:  Kite_kuma
	created: 2020.09.04 17:30:44 */

#include <bits/stdc++.h>
using namespace std;

#pragma region aliases

#define rep(i, n) for(long long i = 0; i < (n); i++)
#define rrep(i, n) for(long long i = (n)-1; i > -1; i--)
#define Rep(i, m, n) for(long long i = (m); i < (n); i++)
#define rRep(i, m, n) for(long long i = (n)-1; i >= (m); i--)
#define REP(i, m, n, p) for(long long i = m; i < n; i += p)
#define foa(s, v) for(auto &s : v)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define bcnt(n) __builtin_popcountll(n)
#define endk endl
#define ednl endl
#define enld endl

using ll = long long;
using ld = long double;
using ull = unsigned long long;
using vb = vector<bool>;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vvvi = vector<vector<vector<int>>>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using mll = map<long long, long long>;
using pll = pair<long long, long long>;
using qll = queue<long long>;
using sll = set<long long>;
using vpll = vector<pair<long long, long long>>;
template <class T = ll>
using V = vector<T>;
template <class T = ll>
using VV = V<V<T>>;
template <class T = ll>
using VVV = V<V<V<T>>>;
//昇順pq(小さい方から取り出す)
template <class T = ll>
using pqup = priority_queue<T, vector<T>, greater<T>>;
//降順pq(大きい方から取り出す)
template <class T = ll>
using pqdn = priority_queue<T>;

#pragma endregion

#pragma region constants

long long const limLL = 9223372036854775807;  // POW(2,63)-1 ~ 9.22e18
long long const dekai = 3e16;
const long double pi = acos(-1);
const char el = '\n';
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};
int ddx[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
int ddy[8] = {-1, 0, 1, -1, 1, -1, 0, 1};

const int mod = 1000000007;
// const int mod = 998244353;

#pragma endregion

#pragma region basic_procedure

template <class T>
inline bool isin(T x, T lef, T rig) {
	return ((lef <= x) && (x < rig));
}

template <class T>
inline bool chmin(T &a, T b) {
	if(a > b) {
		a = b;
		return true;
	}
	return false;
}
template <class T>
inline bool chmax(T &a, T b) {
	if(a < b) {
		a = b;
		return true;
	}
	return false;
}

void Yes(bool f = 1) { cout << (f ? "Yes" : "No") << "\n"; }
void No() { cout << "No\n"; }
void YES(bool f = 1) { cout << (f ? "YES" : "NO") << "\n"; }
void NO() { cout << "NO\n"; }
template <class T>
void drop(T answer) {
	cout << answer << "\n";
	exit(0);
}
void err() {
	cout << -1 << "\n";
	exit(0);
}

vector<long long> vin(long long n) {  //整数n個の入力を受け取ってベクトルに突っ込んで返す
	vector<long long> v(n);
	for(long long i = 0; i < n; i++) {
		cin >> v[i];
	}
	return v;
}

//ベクトルの出力(検証済)
// vectorの中身を出力する 答えの出力に利用可能
template <class T>
void vout(vector<T> &v, bool tate = 0) {
	if(v.size() > 0) {
		for(auto it = v.begin(); it < v.end(); it++) {
			cout << *it;
			if(it != v.end() - 1) {
				if(tate)
					cout << endl;
				else
					cout << " ";
			}
		}
	}
	cout << endl;
}

template <class T>
void add(vector<T> &v, T val) {	 //ベクトルの各要素に加算
	for(auto &a : v) a += val;
	return;
}

// vectorの中身を数える map<要素,個数>を返す
template <class T>
map<T, long long> cntv(vector<T> v) {
	map<T, long long> m;
	for(auto &g : v) {
		if(m.count(g))
			m[g]++;
		else
			m[g] = 1;
	}
	return m;
}

//配列圧縮(検証済)
//{1,36,1,3,8,-2,-92}を
//{2, 5,2,3,4, 1,  0}にする
template <class T>
vector<long long> press(vector<T> &v) {
	long long n = v.size();
	vector<long long> w(n);
	map<T, long long> m;
	for(T &p : v) m[p] = 0;
	long long i = 0;
	for(auto &p : m) {
		p.second = i;
		i++;
	}
	for(long long i = 0; i < n; i++) w.at(i) = m[v.at(i)];
	return w;
}

template <class T>
T divup(T a, T b) {
	//端数繰りあがり割り算
	assert(b != 0);
	T x = abs(a);
	T y = abs(b);
	T z = (x + y - 1) / y;
	if((a < 0 && b > 0) || (a > 0 && b < 0))
		return -z;
	else if(a == 0)
		return 0;
	else
		return z;
}

long long POW(long long a, long long n) {
	long long res = 1;
	while(n > 0) {
		if(n & 1) res = res * a;
		a = a * a;
		n >>= 1;
	}
	return res;
}

template <class T>
int sgn(T x) {	//符号関数
	if(x < 0) return -1;
	if(x == 0) return 0;
	return 1;
}

long long modpow(long long a, long long n, long long mod) {	 // a^n mod
	if(mod == 1) return 0LL;
	long long res = 1;
	while(n > 0) {
		if(n & 1) res = res * a % mod;
		a = a * a % mod;
		n >>= 1;
	}
	return res;
}

// a * x % mod == __gcd(a,mod)なるxを返す
// a が modの倍数でないことが条件
long long modinv(long long a, long long mod) {
	long long b = mod, u = 1, v = 0;
	while(b) {
		long long t = a / b;
		a -= t * b;
		swap(a, b);
		u -= t * v;
		swap(u, v);
	}
	u %= mod;
	if(u < 0) u += mod;
	return u;
}

vvll comb(100, vll(100, -1));
long long com(long long n, long long k) {  //普通の二項計数(overflowに注意)
	assert(n < 100 && k < 100);
	if(n < k || k < 0 || n < 0) return 0;
	if(comb[n][k] != -1) return comb[n][k];
	ll res;
	if(n - k < k)
		res = com(n, n - k);
	else if(k == 0)
		res = 1;
	else
		res = com(n - 1, k - 1) + com(n - 1, k);
	comb[n][k] = res;
	return res;
}

// nCk modを求める
const ll MAX = 5100000;
// この値は求める二項計数の値に応じて変える
// MAX=3*10^7のとき1900msほど、ほぼ比例
// MAX=5*10^6程度ならそれほど気にしなくてよい(300ms程)
long long fac[MAX], finv[MAX], inv[MAX];

void cominit() {
	// テーブルを作る前処理
	fac[0] = fac[1] = 1;
	finv[0] = finv[1] = 1;
	inv[1] = 1;
	for(ll i = 2; i < MAX; i++) {
		fac[i] = fac[i - 1] * i % mod;
		inv[i] = mod - inv[mod % i] * (mod / i) % mod;
		finv[i] = finv[i - 1] * inv[i] % mod;
	}
}
long long commod(ll n, ll k) {	// 二項係数計算
	if(n < k) return 0;
	if(n < 0 || k < 0) return 0;
	return fac[n] * (finv[k] * finv[n - k] % mod) % mod;
}
long long pmod(ll n, ll k) {  //順列計算
	if(n < k) return 0;
	if(n < 0 || k < 0) return 0;
	return fac[n] * finv[n - k] % mod;
}
long long hmod(ll n, ll k) {  // nHk計算
	// n個の区別しないoを区別するk個の箱に入れる方法の総数
	//(n+k-1)C(k-1)と等しい
	return commod(n + k - 1, n);
}
#pragma endregion

#pragma region input
#define VEC(type, name, size) \
	vector<type> name(size);  \
	IN(name)
#define VVEC(type, name, h, w)                     \
	vector<vector<type>> name(h, vector<type>(w)); \
	IN(name)
#define INT(...)     \
	int __VA_ARGS__; \
	IN(__VA_ARGS__)
#define LL(...)            \
	long long __VA_ARGS__; \
	IN(__VA_ARGS__)
#define STR(...)        \
	string __VA_ARGS__; \
	IN(__VA_ARGS__)
#define CHAR(...)     \
	char __VA_ARGS__; \
	IN(__VA_ARGS__)
#define DOUBLE(...)     \
	double __VA_ARGS__; \
	IN(__VA_ARGS__)
#define LD(...)              \
	long double __VA_ARGS__; \
	IN(__VA_ARGS__)

template <class T>
void scan(T &a) {
	cin >> a;
}
template <class T>
void scan(vector<T> &a) {
	for(auto &i : a) scan(i);
}
template <class T, class L>
void scan(pair<T, L> &p) {
	scan(p.first);
	scan(p.second);
}
void IN() {}
template <class Head, class... Tail>
void IN(Head &head, Tail &... tail) {
	scan(head);
	IN(tail...);
}
template <class T>
inline void print(T x) {
	cout << x << '\n';
}

template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) {
	is >> p.first >> p.second;
	return is;
}
#pragma endregion

#pragma region debug

template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
	os << p.first << " " << p.second;
	return os;
}

template <class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
	rep(i, v.size()) {
		if(i) os << " ";
		os << v[i];
	}
	return os;
}

template <typename T>
void view(const std::vector<T> &v) {
	std::cerr << "{ ";
	for(const auto &e : v) {
		std::cerr << e << ", ";
	}
	std::cerr << "\b\b }";
}
template <typename T>
void view(const std::vector<std::vector<T>> &vv) {
	std::cerr << "{\n";
	for(const auto &v : vv) {
		std::cerr << "\t";
		view(v);
		cerr << "\n";
	}
	std::cerr << "}";
}
template <typename T, typename U>
void view(const std::vector<std::pair<T, U>> &v) {
	std::cerr << "{\n";
	for(const auto &c : v) {
		std::cerr << "\t(" << c.first << ", " << c.second << ")\n";
	}
	std::cerr << "}";
}
template <typename T, typename U>
void view(const std::map<T, U> &m) {
	std::cerr << "{\n";
	for(auto &t : m) {
		std::cerr << "\t[" << t.first << "] : " << t.second << "\n";
	}
	std::cerr << "}";
}
template <typename T, typename U>
void view(const std::pair<T, U> &p) {
	std::cerr << "(" << p.first << ", " << p.second << ")";
}
template <typename T>
void view(const std::set<T> &s) {
	std::cerr << "{ ";
	for(auto &t : s) {
		view(t);
		std::cerr << ", ";
	}
	std::cerr << "\b\b }";
}
template <typename T>
void view(T e) {
	std::cerr << e;
}

// when debugging : g++ foo.cpp -DLOCAL
#ifdef LOCAL
void debug_out() {}
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
	view(H);
	cerr << ", ";
	debug_out(T...);
}
#define debug(...)                                           \
	do {                                                     \
		cerr << __LINE__ << " [" << #__VA_ARGS__ << "] : ["; \
		debug_out(__VA_ARGS__);                              \
		cerr << "\b\b]\n";                                   \
	} while(0)
#define dump(x)                                 \
	do {                                        \
		cerr << __LINE__ << " " << #x << " : "; \
		view(x);                                \
		cerr << "\n";                           \
	} while(0)
#else
#define debug(...) (void(0))
#define dump(x) (void(0))
#endif

#pragma endregion

class RollingHash_Mersenne {
	// safety rollinghash (mod : 1UL << 61 - 1, base : 10007 or random)
	// https://atcoder.jp/contests/agc047/submissions/16500504
	const unsigned long long MASK30 = (1ULL << 30) - 1;
	const unsigned long long MASK31 = (1ULL << 31) - 1;
	const unsigned long long MASK61 = (1ULL << 61) - 1;
	const unsigned long long MOD = MASK61;
	const unsigned long long base = 10007;	// 値が小さすぎると衝突しやすい
	const unsigned long long POSITIVIZER = MOD << 2;
	vector<unsigned long long> hash, power;

	// a * b と mod が等しい数を返す
	// 結果は (1UL << 63) + 3 - (1UL << 31) * 3 以下
	unsigned long long Mul(unsigned long long a, unsigned long long b) const {
		unsigned long long au = a >> 31;
		unsigned long long ad = a & MASK31;
		unsigned long long bu = b >> 31;
		unsigned long long bd = b & MASK31;
		unsigned long long mid = ad * bu + au * bd;
		unsigned long long midu = mid >> 30;
		unsigned long long midd = mid & MASK30;
		return au * bu * 2 + midu + (midd << 31) + ad * bd;
	}

	// mod 2^61-1を計算する
	unsigned long long CalcMod(unsigned long long x) const {
		unsigned long long xu = x >> 61;
		unsigned long long xd = x & MASK61;
		unsigned long long res = xu + xd;
		if(res >= MOD) res -= MOD;
		return res;
	}

   public:
	RollingHash_Mersenne() = default;
	RollingHash_Mersenne(const string &s, unsigned long long _base = 10007) : base(_base) {
		int sz = (int)s.size();
		hash.assign(sz + 1, 0);
		power.assign(sz + 1, 0);
		power[0] = 1;
		for(int i = 0; i < sz; i++) {
			power[i + 1] = CalcMod(Mul(power[i], base));
			hash[i + 1] = CalcMod(Mul(hash[i], base) + s[i]);
		}
	}

	template <class T>
	RollingHash_Mersenne(const vector<T> &v, unsigned long long _base = 10007) : base(_base) {
		int sz = (int)v.size();
		hash.assign(sz + 1, 0);
		power.assign(sz + 1, 0);
		power[0] = 1;
		for(int i = 0; i < sz; i++) {
			power[i + 1] = CalcMod(Mul(power[i], base));
			hash[i + 1] = CalcMod(Mul(hash[i], base) + v[i]);
		}
	}

	unsigned long long get(int l, int r) const { return CalcMod(hash[r] + POSITIVIZER - Mul(hash[l], power[r - l])); }

	unsigned long long connect(unsigned long long h1, unsigned long long h2, unsigned long long h2len) const {
		return CalcMod(Mul(h1, power[h2len]) + h2);
	}

	// Longest Common Prefix (using Binary Search)
	int LCP(int l_this, int r_this, RollingHash_Mersenne &other, int l_other, int r_other) {
		int len = min(r_this - l_this, r_other - l_other);
		int low = 0, high = len + 1;
		while(high - low > 1) {
			int mid = (low + high) / 2;
			if(get(l_this, l_this + mid) == other.get(l_other, l_other + mid))
				low = mid;
			else
				high = mid;
		}
		return low;
	}
};

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cout << fixed << setprecision(15);

	INT(n);
	VEC(string, s, n);

	vector<pair<int, string>> ps(n);
	rep(i, n) ps[i] = {(int)s[i].size(), s[i]};
	sort(all(ps));
	rep(i, n) reverse(all(ps[i].second));

	map<ull, int> m;

	ll ans = 0;
	ull r = 10007 + rand() % (ull)1e15;

	rep(i, n) {
		int k;
		string now;
		tie(k, now) = ps[i];
		debug(k, now);
		dump(m);
		auto rhm = RollingHash_Mersenne(now, r);
		vll v(k + 1);
		rrep(j, k) { v[j] = v[j + 1] | (1LL << (now[j] - 'a')); }
		dump(v);
		rep(j, k) {
			dump(j);
			ull hash = rhm.get(0, j);
			dump(hash);
			rep(bit, 26) {
				if(v[j] & 1LL << bit) {
					char c = 'a' + bit;
					ull hash2 = c;
					ull res = rhm.connect(hash, hash2, 1);
					debug(c, hash2, res);
					if(m.count(res)) {
						ans += m[res];
						debug(res, m[res]);
						debug(now.substr(0, j), c);
					}
				}
			}
		}
		ull hash = rhm.get(0, k);
		m[hash]++;
	}
	dump(m);
	drop(ans);
	return 0;
}

// 534 m : {
//         [97] : 0
//         [98] : 0
//         [99] : 0
//         [120] : 0
//         [121] : 0
//         [4453] : 0
//         [4454] : 0
//         [196073] : 1
//         [2216499] : 0
//         [2216521] : 0
//         [40939142969] : 1
// }


Measured memory_bytes: 31624