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
#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
const int MAXN = 1000000;
vector<int> lst[MAXN];
int parent[MAXN];
void make_set(int v) {
  lst[v] = vector<int>(1, v);
  parent[v] = v;
}
int find_set(int v) { return parent[v]; }
void union_sets(int a, int b) {
  a = find_set(a);
  b = find_set(b);
  if (a != b) {
    if (lst[a].size() < lst[b].size()) swap(a, b);
    while (!lst[b].empty()) {
      int v = lst[b].back();
      lst[b].pop_back();
      parent[v] = a;
      lst[a].push_back(v);
    }
  }
}
int main() {
  int N, M;
  scanf("%d %d", &N, &M);
  long long n = N;
  long long m = M;
  std::vector<std::vector<int> > g(n);
  std::vector<int> deg(n, 0);
  for (int i = 0; i < n; i++) make_set(i);
  int s = 0;
  for (int i = 0; i < m; i++) {
    int u, v;
    scanf("%d %d", &u, &v);
    u--;
    v--;
    if (i == 0) {
      s = u;
    }
    deg[u]++;
    deg[v]++;
    union_sets(u, v);
  }
  long long ans = m * (m - 1) / 2;
  for (int i = 0; i < n; i++) {
    if (deg[i] > 0 && find_set(s) != find_set(i)) ans = 0;
  }
  cout << ans;
}
