using System;
using System.Linq;
using System.Collections.Generic;

namespace Contest
{
  class Program
  {
    static void Main(string[] args)
    {
      ABC173.F();
      //ABC173.E_Tester();
    }

    class ABC173
    {
      public static void A()
      {
        var N = Read.Int();
        Console.WriteLine((20000 - N) % 1000);
      }
      public static void B()
      {
        var N = Read.Int();
        var S = Enumerable.Range(0, N).Select(i => Read.Str()).ToArray();
        var freq = Util.Frequency(S);
        Console.WriteLine("AC x {0}", freq.ContainsKey("AC") ? freq["AC"] : 0);
        Console.WriteLine("WA x {0}", freq.ContainsKey("WA") ? freq["WA"] : 0);
        Console.WriteLine("TLE x {0}", freq.ContainsKey("TLE") ? freq["TLE"] : 0);
        Console.WriteLine("RE x {0}", freq.ContainsKey("RE") ? freq["RE"] : 0);
      }
      public static void C()
      {
        var H = Read.Int();
        var W = Read.Int();
        var K = Read.Int();
        var C = Enumerable.Range(0, H).Select(i => Read.Str().Select(c => c == '#').ToArray()).ToArray();
        int count = 0;
        for(int i = 0; i < (1 << H); ++i)
        {
          for(int j = 0; j < (1 << W); ++j)
          {
            int x = 0;
            for(int k = 0; k < H; ++k)
            {
              for(int l = 0; l < W; ++l)
              {
                if(C[k][l] && ((1<<k) & i)>0 && ((1 << l) & j) > 0)
                {
                  x++;
                }
              }
            }
            if (K == x) { count++; }
          }
        }
        Console.WriteLine(count);
      }
      public static void D()
      {
        var N = Read.Int();
        var A = Read.LongN().OrderBy(x => -x).ToArray();
        long ans = 0;
        for(int i = 0; i < N - 1; ++i)
        {
          ans += A[(i + 1) / 2];
        }
        Console.WriteLine(ans);
      }

      public static void E_Tester()
      {
        var N = 6;
        var A = new long[6];
        Random rand = new Random(1);
        for (int i = 0; i < 100; ++i)
        {
          for (int j = 0; j < N; ++j)
          {
            A[j] = rand.Next(j) % 100 - 50;
          }
          for(int k = 1; k <= N; ++k)
          {
            //E(N, k, A);
          }
        }
      }

      //public static void E(int N, int K, long[] A)
      public static void E()
      {
        var N = Read.Int();
        var K = Read.Int();
        var A = Read.LongN();
        var A_Pos = new List<long>();
        var A_Neg = new List<long>();
        foreach(var a in A)
        {
          if (a > 0) { A_Pos.Add(a); }
          if (a < 0) { A_Neg.Add(a); }
        }
        var C_Zero = N - A_Pos.Count - A_Neg.Count;
        var C_Pos = A_Pos.Count;
        var C_Neg = A_Neg.Count;
        if (C_Pos + C_Neg < K) { Console.WriteLine(0); return; }
        if (K - Math.Min(K / 2 * 2, C_Neg / 2 * 2) <= C_Pos)
        {
          A_Pos = A_Pos.OrderBy(x => -x).ToList();
          A_Neg = A_Neg.OrderBy(x => x).ToList();
          MOD ans = 1;
          int count = 0;
          var idxP = 0;
          var idxN = 0;
          while (count < K)
          {
            if (idxN + 2 > C_Neg || K - count < 2)
            {
              ans *= A_Pos[idxP++];
              count++;
            }
            else
            {
              var Neg2 = A_Neg[idxN] * A_Neg[idxN + 1];
              var Pos2 = idxP + 2 > C_Pos ? 0 : A_Pos[idxP] * A_Pos[idxP + 1];
              if (Pos2 > Neg2)
              {
                ans *= A_Pos[idxP++];
                count++;
              }
              else
              {
                ans *= Neg2 % MOD.P;
                idxN += 2;
                count += 2;
              }
            }
          }
          Console.WriteLine(ans.V);          
        }
        else
        {
          if (C_Zero > 0) { Console.WriteLine(0); return; }
          if (C_Pos > 0)
          {
            MOD ans = 1;
            foreach(var a in A)
            {
              ans *= Math.Abs(a);
            }
            ans = 0 - ans;
            Console.WriteLine(ans.V);
          }
          else
          {
            A_Neg = A_Neg.OrderBy(x => -x).ToList();
            MOD ans = 1;
            for (int i = 0; i < K; ++i)
            {
              ans *= Math.Abs(A_Neg[i]);
            }
            ans = 0 - ans;
            Console.WriteLine(ans.V);
          }
        }
      }
      public static void F()
      {
        var N = Read.Int();
        var VW = Read.TupleInt(N - 1);
        long ans = 0;
        for(int i = 0; i < N; ++i)
        {
          ans += (long)(i + 1) * (N - i);
        }
        foreach(var vw in VW)
        {
          var min = Math.Min(vw.Item1, vw.Item2);
          var max = Math.Max(vw.Item1, vw.Item2);
          ans -= (long)min * (N + 1 - max);
        }
        Console.WriteLine(ans);
      }
    }

    class Util
    {
      public static T[,] Gen<T>(int r, int c, T v)
      {
        var matrix = new T[r, c];
        for (int i = 0; i < r; ++i)
        {
          for (int j = 0; j < c; ++j)
          {
            matrix[i, j] = v;
          }
        }
        return matrix;
      }
      public static long[] ASum(long[] array)
      {
        var res = new long[array.Length + 1];
        for (int i = 0; i < array.Length; ++i)
        {
          res[i + 1] = res[i] + array[i];
        }
        return res;
      }
      public static long[,] ASum(long[,] matrix)
      {
        var N = matrix.GetLength(0);
        var M = matrix.GetLength(1);
        var res = new long[N + 1, M + 1];
        for(int i = 0; i < N; ++i)
        {
          for(int j = 0; j < M; ++j)
          {
            res[i + 1, j + 1] = res[i, j + 1] + res[i + 1, j] - res[i, j] + matrix[i, j];
          }
        }
        return res;
      }
      public static Dictionary<T, long> Frequency<T>(T[] array)
      {
        var dict = new Dictionary<T, long>();
        foreach (var a in array)
        {
          if (!dict.ContainsKey(a)) { dict.Add(a, 0); }
          dict[a]++;
        }
        return dict;
      }

    }
    struct MOD
    {
      public static long P = 1000000007;
      public readonly long V;

      public MOD(long a) { this.V = a % P; }
      public static implicit operator MOD(long a) { return new MOD(a); }
      public static MOD operator +(MOD a, MOD b) { return new MOD((a.V + b.V) % P); }
      public static MOD operator -(MOD a, MOD b) { return new MOD((a.V - b.V + P) % P); }
      public static MOD operator *(MOD a, MOD b) { return new MOD((a.V * b.V) % P); }
      public static MOD operator /(MOD a, MOD b) { return new MOD((a.V * b.Inverse().V) % P); }
      public MOD Inverse()
      {
        long a = V, p = P; long b = p, c = 1, d = 0, e = 0, f = 0;
        while (b != 0) { e = a / b; f = b; b = a - e * b; a = f; f = d; d = c - e * d; c = f; }
        c %= p;
        return c + (c < 0 ? p : 0);
      }
      public MOD Power(long n)
      {
        long a = V, p = P; long res = 1; long mult = a;
        for (int i = 0; i < 63; ++i) { if ((n & ((long)1 << i)) > 0) { res = (res * mult) % p; } mult = (mult * mult) % p; }
        return res;
      }
      public override string ToString() { return V.ToString(); }
    }


    static class Read
{
static Queue<string> queue = new Queue<string>();
static void Enqueue() { var ss = Console.ReadLine().Split(' '); foreach (var s in ss) { queue.Enqueue(s); } }
public static int Int() { if (queue.Count == 0) { Enqueue(); } return Convert.ToInt32(queue.Dequeue()); }
public static long Long() { if (queue.Count == 0) { Enqueue(); } return Convert.ToInt64(queue.Dequeue()); }
public static string Str() { if (queue.Count == 0) { Enqueue(); } return queue.Dequeue(); }
public static int[] IntN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToInt32(s)).ToArray(); }
public static long[] LongN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToInt64(s)).ToArray(); }
public static ulong[] ULongN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToUInt64(s)).ToArray(); }
public static string[] StrN() { return Console.ReadLine().Split(' '); }
public static Tuple<int, int>[] TupleInt(int n) { List<Tuple<int, int>> list = new List<Tuple<int, int>>(); for (int i = 0; i < n; ++i) { var ab = Read.IntN(); list.Add(new Tuple<int, int>(ab[0], ab[1])); } return list.ToArray(); }
public static Tuple<long, long>[] TupleLong(int n) { List<Tuple<long, long>> list = new List<Tuple<long, long>>(); for (int i = 0; i < n; ++i) { var ab = Read.LongN(); list.Add(new Tuple<long, long>(ab[0], ab[1])); } return list.ToArray(); }
public static Tuple<string, string>[] TupleStr(int n) { List<Tuple<string, string>> list = new List<Tuple<string, string>>(); for (int i = 0; i < n; ++i) { var ab = Read.StrN(); list.Add(new Tuple<string, string>(ab[0], ab[1])); } return list.ToArray(); }
public static Tuple<double, double>[] TupleDouble(int n) { List<Tuple<double, double>> list = new List<Tuple<double, double>>(); for (int i = 0; i < n; ++i) { var ab = Read.LongN(); list.Add(new Tuple<double, double>(ab[0], ab[1])); } return list.ToArray(); }
public static long[,] LongMatrix(int r, int c) { var mat = new long[r, c]; for (int i = 0; i < r; ++i) { var x = Read.LongN(); for (int j = 0; j < c; ++j) { mat[i, j] = x[j]; } } return mat; }
public static Dictionary<int, HashSet<int>> AdjacencyList(int N, int M, bool isDirectional = false)
{
Dictionary<int, HashSet<int>> dict = new Dictionary<int, HashSet<int>>();
for (int i = 0; i <= N; ++i) { dict.Add(i, new HashSet<int>()); }
        for (int i = 0; i < M; ++i) { var ab = Read.IntN(); if (!dict[ab[0]].Contains(ab[1])) { dict[ab[0]].Add(ab[1]); } if (!isDirectional && !dict[ab[1]].Contains(ab[0])) { dict[ab[1]].Add(ab[0]); } }
        return dict;
}
public static Dictionary<int, Dictionary<int, long>> AdjacencyListWithWeight(int N, int M)
{
Dictionary<int, Dictionary<int, long>> dict = new Dictionary<int, Dictionary<int, long>>(); for (int i = 0; i <= N; ++i) { dict.Add(i, new Dictionary<int, long>()); }
for (int i = 0; i < M; ++i) { var ab = Read.IntN(); dict[ab[0]].Add(ab[1], ab[2]); dict[ab[1]].Add(ab[0], ab[2]); }
return dict;
}
}
    }
}


Measured memory_bytes: 32696