#include #define rep(i, n) for(int i=0, i##_len=(n); i=0; --i) #define rreps(i, n) for(int i=((int)(n)); i>0; --i) #define all(v) (v).begin(), (v).end() using namespace std; using ll = long long; using ull = unsigned long long; using vi = vector; using vvi = vector>; using vvvi = vector>>; using vl = vector; using vvl = vector>; using vvvl = vector>>; using vs = vector; using pi = pair; using pl = pair; templatebool chmax(T &a, const T &b) { if (abool chmin(T &a, const T &b) { if (bbool chmaxeq(T &a, const T &b) { if (a<=b) { a=b; return 1; } return 0; } templatebool chmineq(T &a, const T &b) { if (b<=a) { a=b; return 1; } return 0; } bool yes(bool a) { cout << (a?"yes":"no") << endl; return a; } bool Yes(bool a) { cout << (a?"Yes":"No") << endl; return a; } bool YES(bool a) { cout << (a?"YES":"NO") << endl; return a; } void _main(); int main() { cin.tie(0); ios::sync_with_stdio(0); cout << fixed << setprecision(16); _main(); return 0; } void _main() { int N; cin >> N; vs S(N); rep(i, N) cin >> S[i]; set s; rep(i, N) rep(j, N) { if (i == j) continue; s.insert(S[i] + S[j]); } cout << s.size() << endl; }