#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
#define all(a) a.begin(), a.end()
#define sz(a) ((int)a.size())
#define pb push_back
#ifdef Doludu
template <typename T>
ostream& operator << (ostream &o, vector<T> vec) {
    o << "{"; int f = 0;
    for (T i : vec) o << (f++ ? " " : "") << i;
    return o << "}";
}
void bug__(int c, auto ...a) {
    cerr << "\e[1;" << c << "m";
    (..., (cerr << a << " "));
    cerr << "\e[0m" << endl;
}
#define bug_(c, x...) bug__(c, __LINE__, "[" + string(#x) + "]", x)
#define bug(x...) bug_(32, x)
#define bugv(x...) bug_(36, vector(x))
#define safe bug_(33, "safe")
#else
#define bug(x...) void(0)
#define bugv(x...) void(0)
#define safe void(0)
#endif
const int mod = 998244353, N = 200087;

typedef unsigned long long ull;
ull seed = 56562;
ull shift(ull x) {
    x ^= x << 13;
    x ^= x >> 7;
    x ^= x << 17;
    return x;
}

int main() {
    ios::sync_with_stdio(false), cin.tie(0);
    int n;
    cin >> n;
    vector <vector <int>> adj(n);
    for (int i = 0, u, v; i < n - 1; ++i) {
        cin >> u >> v, --u, --v;
        adj[u].pb(v), adj[v].pb(u);
    }
    vector <ull> down(n), up(n), cur(n);
    auto dfs = [&](auto self, int v, int pa) -> void {
        down[v] = seed;
        for (int u : adj[v]) if (u != pa) {
            self(self, u, v);
            down[v] += shift(down[u]);
        }
    };
    auto dfs2 = [&](auto self, int v, int pa) -> void {
        ull tmp = seed;
        tmp += shift(up[v]);
        for (int u : adj[v]) if (u != pa) {
            tmp += shift(down[u]);
        }
        for (int u : adj[v]) if (u != pa) {
            tmp -= shift(down[u]);
            up[u] = tmp;
            self(self, u, v);
            tmp += shift(down[u]);
        }
    };
    dfs(dfs, 0, -1);
    dfs2(dfs2, 0, -1);
    for (int i = 0; i < n; ++i) {
        if (i) cur[i] = down[i] + shift(up[i]);
        else cur[i] = down[i];
    }
    map <ull, int> cnt;
    for (int i = 0; i < n; ++i) {
        bug(cur[i]);
        cnt[cur[i]]++;
    }
    ll ans = 1ll * sz(cnt) * sz(cnt);
    for (auto [x, y] : cnt) {
        if (y > 1) ans++;
    }
    cout << ans << "\n";
}