import java.util.*; import java.io.*; public class Main { static long[] cum; public static void main(String[] args) throws Exception { FastScanner sc = new FastScanner(System.in); long mod = (long)Math.pow(10,9)+7; int n = sc.nextInt(); int[] from = new int[n+1]; cum = new long[n+1]; ArrayList> map = new ArrayList<>(); for(int i = 0; i <= n; i++){ map.add(new ArrayList<>()); if(i != 0){ cum[i] += cum[i-1]+i; } } for(int i = 0; i < n-1; i++){ int a = sc.nextInt(); int b = sc.nextInt(); from[b] = a; map.get(a).add(b); } int root = 0; for(int i = 1; i <= n; i++){ if(from[i] == 0){ root = i; break; } } //System.out.println(root); boolean[] arrived = new boolean[n+1]; arrived[root] = true; long ans = dfs(map,root,0,arrived); System.out.println(ans); } public static long dfs(ArrayList> map, int now, int dist, boolean[] arrived){ long ret = 0; for(int next : map.get(now)){ if(!arrived[next]){ ret += cum[dist+1]; arrived[now] = true; ret += dfs(map,next,dist+1,arrived); arrived[now] = false; } } return ret; } } class Combination { final static long mod = (long)Math.pow(10,9)+ 7; private static long[] fact, ifact; public Combination(int n){ fact = new long[n+1]; ifact = new long[n+1]; fact[0] = 1; long ln = n; for (long i = 1; i <= ln; ++i){ int ii = (int)i; fact[ii] = fact[ii-1]%mod * i % mod; } ifact[n] = pow(fact[n],this.mod-2); for (int i = n; i >= 1; --i){ int ii = (int)i; ifact[ii-1] = ifact[ii]%mod*i%mod; } } public static long comb(int n, int k){ if (k < 0 || k > n) return 0; return fact[n] % mod * ifact[k] % mod * ifact[n-k] % mod; } public static long perm(int n, int k){ return comb(n,k) * fact[k] % mod; } public static long pow(long a,long b) { long ret = 1; long tmp = a; while(b>0) { if((b&1)==1){ ret = (ret * tmp) % mod; } tmp = (tmp * tmp) % mod; b = b>>1; } return ret; } } class FastScanner { private BufferedReader reader = null; private StringTokenizer tokenizer = null; public FastScanner(InputStream in) { reader = new BufferedReader(new InputStreamReader(in)); tokenizer = null; } public String next() { if (tokenizer == null || !tokenizer.hasMoreTokens()) { try { tokenizer = new StringTokenizer(reader.readLine()); } catch (IOException e) { throw new RuntimeException(e); } } return tokenizer.nextToken(); } public String nextLine() { if (tokenizer == null || !tokenizer.hasMoreTokens()) { try { return reader.readLine(); } catch (IOException e) { throw new RuntimeException(e); } } return tokenizer.nextToken("\n"); } public long nextLong() { return Long.parseLong(next()); } public int nextInt() { return Integer.parseInt(next()); } public double nextDouble() { return Double.parseDouble(next()); } public String[] nextArray(int n) { String[] a = new String[n]; for (int i = 0; i < n; i++) a[i] = next(); return a; } public int[] nextIntArray(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } public long[] nextLongArray(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nextLong(); return a; } }