100 10
87 73
15 71
14 33
1 4
20 80
65 67
36 36
25 4
22 21
7 97
 4 2
3 3
3 4
 5 4
3 3
4 4
5 5
1 2
 4 4
1 2
2 3
3 1
4 4
 4 3
1 1
2 3
3 4
 1000000 1
255765 255765
 4 3
1 2
2 3
4 4
 4 2
1 1
1 2
 3 3
1 1
2 2
3 3
 5 4
1 1
2 3
2 4
2 5
 4 5
1 4
3 4
1 2
2 3
2 4
 4 4
2 3
2 4
3 4
4 4
 10 9
8 10
3 10
2 8
9 3
4 8
1 10
7 9
5 4
7 3
 10 10
1 2
2 3
3 4
4 5
5 1
6 6
7 7
8 8
9 9
10 10
 5 5
1 4
3 4
1 2
2 3
2 4
 3 3
1 2
2 2
3 3
 5 3
1 1
2 2
3 3
 6 12
1 2
1 3
2 3
1 1
2 2
3 3
4 5
5 6
4 6
4 4
5 5
6 6
 4 4
1 2
2 3
1 3
4 4
 5 4
1 2
3 3
4 4
5 5
 7 13
6 7
2 7
3 7
4 3
5 2
1 4
7 7
3 1
5 5
3 3
1 5
2 6
6 6
 2 2
1 1
2 2
 5 5
1 1
2 2
3 3
4 4
5 5
 1 1
1 1
 7 3
1 1
3 3
6 6
 3 3
1 1
2 3
3 3

0 1 0 0 0 0 0 1 0 0 8 6 12 0 8 0 0 0 0 0 57 0 0 0 0 0
import java.io.*;
import java.util.*;

public class Main {
    static int max(int a[]) {
        int ans = Integer.MIN_VALUE;
        for (int i : a) ans = Math.max(ans, i);
        return ans;
    }

    static int max(ArrayList<Integer> a) {
        int ans = Integer.MIN_VALUE;
        for (int i : a) ans = Math.max(ans, i);
        return ans;
    }

    static int min(int a[]) {
        int ans = Integer.MAX_VALUE;
        for (int i : a) ans = Math.min(ans, i);
        return ans;
    }

    static int min(ArrayList<Integer> a) {
        int ans = Integer.MAX_VALUE;
        for (int i : a) ans = Math.min(ans, i);
        return ans;
    }

    static int cnt(int a[], int num) {
        int ans = 0;
        for (int i : a) if (i == num) ans++;
        return ans;
    }

    static int cnt(ArrayList<Integer> a, int num) {
        int ans = 0;
        for (int i : a) if (i == num) ans++;
        return ans;
    }

    static int cnt(boolean a[]) {
        int ans = 0;
        for (int i = 0; i < a.length; i++) if (a[i]) ans++;
        return ans;
    }

    static void fill(int a[], int num) {
        for (int i = 0; i < a.length; i++) a[i] = num;
    }


    static int inf = (int) 1e9 + 7;


    public static void main(String[] args) throws IOException {
        sc = new Scanner(System.in);
        pw = new PrintWriter(System.out);
        int n = sc.nextInt();
        int m = sc.nextInt();
        dsu a = new dsu(n);
        for(int i = 0;i < m;i++) {
            int v1 = sc.nextInt() - 1;
            int v2 = sc.nextInt() - 1;
            a.union(v1, v2);
        }
        if (a.cnt == 1) pw.println((long)m * (m - 1) / 2);
        else pw.println(0);
        pw.close();
    }

    static Scanner sc;
    static PrintWriter pw;

    static class Scanner {
        BufferedReader br;
        StringTokenizer st = new StringTokenizer("");

        Scanner(InputStream in) throws FileNotFoundException {
            br = new BufferedReader(new InputStreamReader(in));
        }

        Scanner(String in) throws FileNotFoundException {
            br = new BufferedReader(new FileReader(in));
        }

        String next() throws IOException {
            while (!st.hasMoreTokens()) st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }

        int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

        long nextLong() throws IOException {
            return Long.parseLong(next());
        }

        double nextDouble() throws IOException {
            return Double.parseDouble(next());
        }
    }
}

class dsu {
    int parent[];
    int cnt;
    dsu(int n) {
        parent = new int [n];
        for(int i = 0;i < n;i++) parent[i] = i;
        cnt = n;
    }

    int get(int v) {
        if (v == parent[v]) return v;
        return parent[v] = get(parent[v]);
    }

    void union(int a, int b) {
        if (get(a) != get(b)) cnt--;
        parent[get(a)] = get(b);
    }
}