#include <bits/stdc++.h>
#define fi first
#define se second
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define rng(a) a.begin(),a.end()
#define rrng(a) a.rbegin(),a.rend()
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define uni(x) x.erase(unique(rng(x)),x.end())
#define snuke srand((unsigned)clock()+(unsigned)time(NULL));
#define show(x) cerr<<#x<<" = "<<x<<endl;
#define PQ(T) priority_queue<T,v(T),greater<T> >
#define bn(x) ((1<<x)-1)
#define dup(x,y) (((x)+(y)-1)/(y))
#define newline puts("")
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
typedef long long int ll;
typedef unsigned uint;
typedef unsigned long long ull;
typedef pair<int,int> P;
typedef tuple<int,int,int> T;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<P> vp;
typedef vector<T> vt;
int getInt(){int x;scanf("%d",&x);return x;}
template<typename T>istream& operator>>(istream&i,v(T)&v){rep(j,sz(v))i>>v[j];return i;}
template<typename T>string join(const v(T)&v){stringstream s;rep(i,sz(v))s<<' '<<v[i];return s.str().substr(1);}
template<typename T>ostream& operator<<(ostream&o,const v(T)&v){if(sz(v))o<<join(v);return o;}
template<typename T1,typename T2>istream& operator>>(istream&i,pair<T1,T2>&v){return i>>v.fi>>v.se;}
template<typename T1,typename T2>ostream& operator<<(ostream&o,const pair<T1,T2>&v){return o<<v.fi<<","<<v.se;}
template<typename T>bool mins(T& x,const T&y){if(x>y){x=y;return true;}else return false;}
template<typename T>bool maxs(T& x,const T&y){if(x<y){x=y;return true;}else return false;}
template<typename T>ll suma(const v(T)&a){ll res(0);for(auto&&x:a)res+=x;return res;}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#define dame { puts("-1"); return 0;}
#define yn {puts("Yes");}else{puts("No");}
const int MX = 1000005;
typedef v(string) vs;

// rolling hash
// mod pair for hash
const int p1 = 33487;
struct mints {
  template<int mod>
  struct mint {
    ll x;
    mint(ll x=0):x(x){}
    mint& operator+=(const mint& a){ if((x+=a.x)>=mod) x-=mod; return *this;}
    mint& operator-=(const mint& a){ if((x+=mod-a.x)>=mod) x-=mod; return *this;}
    mint& operator*=(const mint& a){ (x*=a.x)%=mod; return *this;}
    mint& operator/=(const mint& a){ (x*=a.ex(mod-2).x)%=mod; return *this;}
    mint operator+(const mint& a)const{ return mint(*this) += a;}
    mint operator-(const mint& a)const{ return mint(*this) -= a;}
    mint operator*(const mint& a)const{ return mint(*this) *= a;}
    mint operator/(const mint& a)const{ return mint(*this) /= a;}
    bool operator<(const mint& a)const{ return x < a.x;}
    bool operator==(const mint& a)const{ return x == a.x;}
    mint ex(ll t) const {
      if(!t) return 1;
      mint res = ex(t/2);
      res *= res;
      return (t&1)?res*x:res;
    }
  };
  mint<1011235817> x;
  mint<987654347> y;
  mints(ll x=0):x(x),y(x){}
  mints& operator+=(const mints& a){ x+=a.x; y+=a.y; return *this;}
  mints& operator-=(const mints& a){ x-=a.x; y-=a.y;  return *this;}
  mints& operator*=(const mints& a){ x*=a.x; y*=a.y;  return *this;}
  mints& operator/=(const mints& a){ x/=a.x; y/=a.y;  return *this;}
  mints operator+(const mints& a)const{ return mints(*this) += a;}
  mints operator-(const mints& a)const{ return mints(*this) -= a;}
  mints operator*(const mints& a)const{ return mints(*this) *= a;}
  mints operator/(const mints& a)const{ return mints(*this) /= a;}
  bool operator<(const mints& a)const{ return (x==a.x)?(y<a.y):(x<a.x);}
  bool operator==(const mints& a)const{ return x==a.x && y==a.y;}
  ll get() const { return x.x<<32|y.x;}
};
ostream& operator<<(ostream&o,const mints&a){o<<a.x.x*int(1e9)+a.y.x;return o;}
typedef vector<mints> vm;
//
struct Hash {
  int n;
  vm h, p;
  Hash() {}
  Hash(const string& s) {
    n = sz(s);
    h = p = vm(n+1);
    p[0] = 1;
    rep(i,n) {
      h[i+1] = h[i]*p1+s[i];
      p[i+1] = p[i]*p1;
    }
  }
  mints get(int l, int r) {
    return h[r]-h[l]*p[r-l];
  }
  bool same(int i, int j, int w) {
    return get(i,i+w) == get(j,j+w);
  }
};
//


int main() {
  int n;
  scanf("%d",&n);
  vs s(n);
  cin>>s;
  vvi ss(MX);
  rep(i,n) {
    reverse(rng(s[i]));
    ss[sz(s[i])].pb(i);
  }
  vi is;
  vvi a(n,vi(26));
  v(Hash) h(n);
  rep(i,n) {
    h[i] = Hash(s[i]);
  }
  ll ans = 0;
  drep(l,MX) if (l) {
    unordered_map<ll,int> mp;
    for (int i : is) {
      int c = s[i][l-1]-'a';
      a[i][c] = 1;
      mints x = h[i].h[l-1]*p1;
      rep(j,26) if (a[i][j]) {
        mp[(x+('a'+j)).get()]++;
      }
    }
    for (int i : ss[l]) {
      mints x = h[i].h[l];
      ans += mp[x.get()];
    }
    for (int i : ss[l]) {
      int c = s[i][l-1]-'a';
      a[i][c] = 1;
      is.pb(i);
    }
  }
  cout<<ans<<endl;
  return 0;
}






















Measured memory_bytes: 125240