#include <iostream>
#include <string>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <unordered_map>
#include <map>
#include <set>
#include <algorithm>
#include <queue>
#include <stack>
#include <functional>
#include <bitset>
#include <assert.h>
#include <unordered_map>
#include <fstream>
#include <ctime>
#include <complex>
using namespace std;
typedef long long ll;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<char> vc;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef vector<double> vd;
typedef pair<ll,ll> P;
typedef pair<int,int> pii;
typedef vector<P> vpl;
typedef tuple<ll,ll,ll> tapu;
#define rep(i,n) for(int i=0; i<(n); i++)
#define REP(i,a,b) for(int i=(a); i<(b); i++)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
const int inf = 1<<30;
const ll linf = 1LL<<62;
const int MAX = 510000;
ll dy[8] = {1,-1,0,0,1,-1,1,-1};
ll dx[8] = {0,0,1,-1,1,-1,-1,1};
const double pi = acos(-1);
const double eps = 1e-7;
template<typename T1,typename T2> inline bool chmin(T1 &a,T2 b){
	if(a>b){
		a = b; return true;
	}
	else return false;
}
template<typename T1,typename T2> inline bool chmax(T1 &a,T2 b){
	if(a<b){
		a = b; return true;
	}
	else return false;
}
template<typename T> inline void print(T &a){
    rep(i,a.size()) cout << a[i] << " ";
    cout << "\n";
}
template<typename T1,typename T2> inline void print2(T1 a, T2 b){cout << a << " " << b << "\n";}
template<typename T1,typename T2,typename T3> inline void print3(T1 a, T2 b, T3 c){
	cout << a << " " << b << " " << c << "\n";
}
ll pcount(ll x) {return __builtin_popcountll(x);}
//const int mod = 1e9 + 7;
const int mod = 998244353;

template<typename T> struct BIT{
	vector<T> dat;
	ll sz;
	//all 1-indexed
	BIT(ll sz) : sz(sz){
		dat.assign(++sz, 0);
	}

	T sum(ll k){
		T ret = 0;
		for(++k; k > 0; k -= k & -k) ret += dat[k];
		return (ret);
	}

	void add(ll k, T x){
		for(++k; k < dat.size(); k += k & -k) dat[k] += x;
	}
	
	ll get(T k){
		if(k <= 0) return 0; 
		ll ret = 0;
		int n = 1; while(n < sz) n *= 2;
		for(int i=n/2; i>0; i/=2){
			if(ret+i < sz && dat[ret+i] < k){
				k -= dat[ret+i];
				ret += i;
			}
		}
		return ret;
	}
};

int main(){
	int n; cin >> n;
	vs s(n); rep(i,n) cin >> s[i];
	vector<pair<string,char>> t(n);
	int mx = 0;
	rep(i,n){
		chmax(mx, s[i].size());
		reverse(all(s[i]));
		t[i].second = s[i].back();
		s[i].pop_back();
		t[i].first = s[i];
	}
	mx += 10;
	sort(all(t));
	vector<vector<int>> ls(n,vector<int>(26,0));
	rep(i,n){
		for(auto j : t[i].first) ls[i][j-'a']++;
		ls[i][t[i].second-'a']++;
	}
	int pre = -1;
	vector<BIT<int>> cnt(26,BIT<int>(mx));
	ll ans = 0;
	rep(i,n){
		int l=i, r=n;
		while(r-l > 1){
			ll m = (l+r)/2;
			bool f = true;
			rep(j,t[i].first.size()){
				if(t[i].first[j] < t[m].first[j]){
					f = false;
					break;
				}
			}
			if(f) l = m;
			else r = m;
		}
		if(l > pre){
			for(int j=l; j>i; j--){
				rep(k,26) cnt[k].add(ls[j][k],1);
			}
		}else{
			rep(k,26) cnt[k].add(ls[i][k],-1);
			for(int j=pre; j>l; j--){
				rep(k,26) cnt[k].add(ls[j][k],-1);
			}
		}
		char c = t[i].second;
		ans += cnt[c-'a'].sum(mx-1) - cnt[c-'a'].sum(ls[i][c-'a']-1);
		pre = l;
	}
	cout << ans << "\n";
}

Measured memory_bytes: 108844