#include<bits/stdc++.h>

using namespace std;

#define fRead(x)        freopen(x,"r",stdin)
#define fWrite(x)       freopen (x,"w",stdout)

#define LL              long long
#define ULL             unsigned long long
#define ff              first
#define ss              second
#define pb              push_back
#define PI              acos(-1.0)
#define mk              make_pair
#define pii             pair<int,int>
#define pll             pair<LL,LL>


#define min3(a,b,c)     min(a,min(b,c))
#define max3(a,b,c)     max(a,max(b,c))
#define min4(a,b,c,d)   min(a,min(b,min(c,d)))
#define max4(a,b,c,d)   max(a,max(b,max(c,d)))
#define SQR(a)          ((a)*(a))
#define FOR(i,a,b)      for(int i=a;i<=b;i++)
#define ROF(i,a,b)      for(int i=a;i>=b;i--)
#define REP(i,b)        for(int i=0;i<b;i++)
#define MEM(a,x)        memset(a,x,sizeof(a))
#define ABS(x)          ((x)<0?-(x):(x))

#define SORT(v)         sort(v.begin(),v.end())
#define REV(v)          reverse(v.begin(),v.end())
//#pragma GCC target ("avx2")
//#pragma GCC optimization ("O2")
//#pragma GCC optimization ("unroll-loops")
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define FastRead        ios_base::sync_with_stdio(0);cin.tie(nullptr);
#ifdef VAMP
     #define debug(...) __f(#__VA_ARGS__, __VA_ARGS__)
    template < typename Arg1 >
    void __f(const char* name, Arg1&& arg1){
        cout << name << " = " << arg1 << std::endl;
    }
    template < typename Arg1, typename... Args>
    void __f(const char* names, Arg1&& arg1, Args&&... args){
        const char* comma = strchr(names+1, ',');
        cout.write(names, comma - names) << " = " << arg1 <<" | ";
        __f(comma+1, args...);
    }
#else
    #define debug(...)
#endif

const int N = 200005;
const int M = 2000005;
int trie[M][26] , mark[M][26];

vector<string>vec;
int n , id = 1;

void Insert(string &s){
    int row = 1;
    vector<int>nodes;
    for(int i = 0;i < s.size();i++){
        int d = s[i] - 'a';
        if(trie[row][d] == 0){
            trie[row][d] = ++id;
        }
        row = trie[row][d];
        nodes.push_back(row);
    }

    int cnt[26];MEM(cnt,0);
    for(int i = s.size() - 1;i >= 0;i--){
        int d = s[i] - 'a';
        int now = nodes[i];
        cnt[d] = 1;
        for(int j = 0;j < 26;j++){
            mark[now][j] += cnt[j];
        }
    }
    for(int j = 0;j < 26;j++){
        mark[1][j] += cnt[j];
    }
}
LL query(string &s){
    int row = 1;
    for(int i = 0;i < (int)s.size() - 1;i++){
        int d = s[i] - 'a';
        row = trie[row][d];
        if(row == 0)return 0;
    }
//    debug(row);
    int d = s.back() - 'a';
    LL ans = 0;
    for(int i = 0;i < 26;i++){
        int now = trie[row][i];
        if(now == 0)continue;
        ans += mark[now][d];
    }

    return ans;
}
int32_t main()
{
    #ifdef VAMP
        clock_t tStart = clock();
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif
    FastRead
    cin >> n;
    REP(i,n){
        string s;cin >> s;
        REV(s);
        vec.push_back(s);
    }
    sort(vec.begin(),vec.end(),[](string &a,string &b){
        return a.size() > b.size();
    });
    LL ans = 0;
    for(int i = 0;i < vec.size();i++){
        ans += query(vec[i]);
        Insert(vec[i]);
    }
    cout << ans << "\n";
    #ifdef VAMP
        fprintf(stderr, "\n>> Runtime: %.10fs\n", (double) (clock() - tStart) / CLOCKS_PER_SEC);
    #endif
}


Measured memory_bytes: 207672