#include <bits/stdc++.h>
#define vi vector<int>
using namespace std;

const int N = 1005;
int n, cnt[N][N], id[N], m;
string s;
map<vi, bool> mem;

bool dfs(vi a) {
    if (mem.count(a)) return mem[a];
    int p = a[9];
    for (int i = 0; i < 3; ++i) if (a[p * 3 + i]) {
        vi b = a;
        b[p * 3 + i]--;
        b[9] = i;
        if (!dfs(b)) return mem[a] = 1;
    }
    return mem[a] = 0;
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    cin >> n;
    for (int i = 1; i <= n; ++i) {
        cin >> s;
        char S = s[0], T = s[s.size() - 1];
        if (!id[S]) id[S] = ++m;
        if (!id[T]) id[T] = ++m;
        cnt[id[S]-1][id[T]-1]++;
    }
    int ans = 0;
    for (int si = 0; si < 3; ++si) 
        for (int sj = 0; sj < 3; ++sj)
            if (cnt[si][sj]) {
                vi a(10);
                for (int i = 0; i < 3; ++i) for (int j = 0; j < 3; ++j) a[i * 3 + j] = cnt[i][j];
                a[si * 3 + sj]--; a[9] = sj;
                if (!dfs(a)) ans += cnt[si][sj];
            }
    cout << ans << endl;
    return 0;
}