import java.util.*;
import java.io.*;
 
public class Main {
    static boolean[] arrived;
    static long[] cum;
    public static void main(String[] args) throws Exception {
        FastScanner sc = new FastScanner(System.in);
        int n = sc.nextInt();
        int[] from = new int[n+1];
        cum = new long[n+1];
        ArrayList<ArrayList<Integer>> 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;
            }
        }
        arrived = new boolean[n+1];
        arrived[root] = true;
        long ans = dfs(map,root,0);
        System.out.println(ans);
    }
    
    public static long dfs(ArrayList<ArrayList<Integer>> map, int now, int dist){
        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[now] = false;
            }
        }
        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;
    } 
}