#include <iostream>
#include <cstring>
#include <algorithm>
#include <vector>
#include <string>
#include <math.h>
#include <iomanip>
#include <limits>
#include <list>
#include <queue>
#include <tuple>
#include <map>
#include <stack>
#include <set>
#include <bitset>
#include <functional>
#include <cassert>
using namespace std;
#define fast_io ios_base::sync_with_stdio (false) ; cin.tie(0) ; cout.tie(0) ;
#define ll long long int
#define rep(i,n) for(int i=0; i<(int)(n); i++)
#define reps(i,n) for(int i=1; i<=(int)(n); i++)
#define REP(i,n) for(int i=n-1; i>=0; i--)
#define REPS(i,n) for(int i=n; i>0; i--)
#define MOD (long long int)(1e9+7)
#define INF (int)(1e9)
#define LINF (long long int)(1e18)
#define chmax(a, b) a = (((a)<(b)) ? (b) : (a))
#define chmin(a, b) a = (((a)>(b)) ? (b) : (a))
#define all(v) v.begin(), v.end()
typedef pair<int, int> Pii;
typedef pair<ll, ll> Pll;

ll mpow(ll a, ll b){
  if(b==0) return 1;
  else if(b%2==0){ll memo = mpow(a,b/2); return memo*memo%MOD;}
  else return mpow(a,b-1) * a % MOD;
}
ll lpow(ll a, ll b){
  if(b==0) return 1;
  else if(b%2==0){ll memo = lpow(a,b/2); return memo*memo;}
  else return lpow(a,b-1) * a;
}
ll gcd(ll a, ll b){
  if(b==0) return a;
  else return gcd(b, a%b);
}
vector<ll> kaijo_memo;
ll kaijo(ll n){
  if(kaijo_memo.size() > n) return kaijo_memo[n];
  if(kaijo_memo.size() == 0) kaijo_memo.push_back(1);
  while(kaijo_memo.size() <= n) kaijo_memo.push_back(kaijo_memo[kaijo_memo.size()-1] * kaijo_memo.size() % MOD);
  return kaijo_memo[n];
}
vector<ll> gyaku_kaijo_memo;
ll gyaku_kaijo(ll n){
  if(gyaku_kaijo_memo.size() > n) return gyaku_kaijo_memo[n];
  if(gyaku_kaijo_memo.size() == 0) gyaku_kaijo_memo.push_back(1);
  while(gyaku_kaijo_memo.size() <= n) gyaku_kaijo_memo.push_back(gyaku_kaijo_memo[gyaku_kaijo_memo.size()-1] * mpow(gyaku_kaijo_memo.size(), MOD-2) % MOD);
  return gyaku_kaijo_memo[n];
}

ll nCr(ll n, ll r){
  if(n == r) return 1;//0個の丸と-1個の棒みたいな時に時に効く？不安.
  if(n < r || r < 0) return 0;
  ll ret = 1;
  if(n <= 1e7){
    ret *= kaijo(n); ret %= MOD;
    ret *= gyaku_kaijo(r); ret %= MOD;
    ret *= gyaku_kaijo(n-r); ret %= MOD;
  }else{
    rep(i,r){
      ret *= n-i; ret %= MOD;
      ret *= mpow(r-i, MOD-2); ret %= MOD;
    }
  }
  return ret;
}

ll ans = 0;
struct Node{
  char moji; vector<int> num; vector<int> next;
};
vector<Node> nodes;
vector<string> S;
int n_end = 0;
//i,j,k = 文字iがSjのk文字以降にあるか
vector<vector<bool>> exist[26]; 

bool saiki(int si, int idx, int now){
  rep(c,26){
    if(nodes[now].num[c] > 0){
      if(exist[c][si][idx]){
        //cout<<si<<" "<<S[si]<<" "<<idx<<" "<<c<<endl;
        ans += nodes[now].num[c];
      }
    }
  }
  //cerr<<si<<" "<<now<<endl;

  if(idx == S[si].size()){
    return true;
  }

  int c = S[si][idx] - 'a';
  if(nodes[now].next[c] == -1){
    nodes[now].next[c] = n_end;
    nodes.push_back(Node());
    nodes[n_end].moji = S[si][idx];
    nodes[n_end].num = vector<int>(26, 0);
    nodes[n_end].next = vector<int>(26, -1);
    n_end++;
  }

  int next = nodes[now].next[c];

  bool final = saiki(si, idx+1, next);
  if(final){
    nodes[now].num[S[si][idx] - 'a']++;
  }
  return false;
}

bool comp(const string& a, const string& b){
  return a.size() < b.size();
}

int main(void){
  fast_io
  cout<<fixed<<setprecision(15);

  int n;cin>>n;
  rep(c,26){
    exist[c] = vector<vector<bool>>(n);
  }
  rep(i,n){
    string s;cin>>s;
    reverse(all(s));
    S.push_back(s);
  }

  sort(all(S), comp);
  rep(i,n){
    string s = S[i];
    rep(c,26){
      exist[c][i] = vector<bool>(s.size(), false);
      REP(j,s.size()){
        exist[c][i][j] = s[j] - 'a' == c;
        if(j != s.size() - 1){
          exist[c][i][j] = exist[c][i][j] | exist[c][i][j+1];
        }
      }
    }
  }
  nodes.push_back(Node());
  nodes[n_end].moji = -1;
  nodes[n_end].num = vector<int>(26, 0);
  nodes[n_end].next = vector<int>(26, -1);
  n_end++;
  rep(si,n){
    saiki(si, 0, 0);
  }
  cout<<ans<<endl;
  return 0;
}

Measured memory_bytes: 473376