bool debug = false;
#include <iostream>
#include <utility>
using namespace std;

#define F first
#define S second

constexpr int kN = int(4E5 + 10), kInf = int(1E9 + 10);

struct seg_tree {
	pair<int, int> p[kN << 2];
	void pull(int n) {
		if (p[(n << 1) + 1].F < p[(n << 1) + 2].F) p[n] = p[(n << 1) + 1];
		else if (p[(n << 1) + 1].F == p[(n << 1) + 2].F) {
			if (p[(n << 1) + 1].S & 1) p[n] = p[(n << 1) + 2];
			else p[n] = p[(n << 1) + 1];
		}
		else p[n] = p[(n << 1) + 2];
		return ;
	}
	void init(int n, int l, int r, int a[]) {
		if (l == r) p[n] = {a[l], l};
		else {
			int mid = (l + r) >> 1;
			init((n << 1) + 1, l, mid, a);
			init((n << 1) + 2, mid + 1, r, a);
			pull(n);
		}
		return ;
	}
	pair<int, int> ask(int n, int l, int r, int L, int R) {
		if (L <= l && r <= R) return p[n];
		else if (l > R || L > r) return {kInf, l};
		else {
			int mid = (l + r) >> 1;
			pair<int, int> lans = ask((n << 1) + 1, l, mid, L, R), rans = ask((n << 1) + 2, mid + 1, r, L, R);
			if (lans.F < rans.F) return lans;
			else if (lans.F == rans.F) {
				if (lans.S & 1) return rans;
				else return lans;
			}
			else return rans;
		}
	}
};

int LCP(string &a, string &b) {
	int sz = min(int(a.size()), int(b.size()));
	for (int i = 0; i < sz; i++) if (a[i] != b[i]) return i;
	return sz;
}

seg_tree sg;
int a[kN], tot;

long long int dp(int l, int r) {
	if (l > r) return 0;
	pair<int, int> tmp = sg.ask(0, 1, tot, l, r);
	long long int fl, fr, L, R, ans = 0;
	if (!(tmp.S & 1)) L = tmp.S - 1, R = tmp.S + 1;
	else L = R = tmp.S;
	if (debug) printf("l = %d, r = %d, tmp = (%d, %d), L = %lld, R = %lld, ", l, r, tmp.F, tmp.S, L, R);
	fl = l >> 1;
	fr = r >> 1;
	L >>= 1;
	R >>= 1;
	ans += (L - fl + 1) * (fr - R + 1) * (fr + R - fl - L + 2) / 2;
	if (debug) printf("ans = %lld\n", ans * tmp.F); 
	if (tmp.S & 1) return ans * tmp.F + dp(l, tmp.S - 2) + dp(tmp.S + 2, r);
	return ans * tmp.F + dp(l, tmp.S - 1) + dp(tmp.S + 1, r);
}

int main() {
	int n;
	string s[2];
	cin >> n >> s[1];
	a[1] = int(s[1].size());
	for (int i = 2; i <= n; i++) {
		cin >> s[i & 1];
		a[(i << 1) - 2] = LCP(s[0], s[1]);
		a[(i << 1) - 1] = int(s[i & 1].size());
	}
	tot = (n << 1) - 1;
	sg.init(0, 1, tot, a);
	printf("%lld\n", dp(1, tot));
}