#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")


template <class T> void bAdd(vector<T> &bit, int pos, const T &val) {
  const int bitN = bit.size();
  for (int x = pos; x < bitN; x |= x + 1) bit[x] += val;
}
template <class T> T bSum(const vector<T> &bit, int pos) {
  T ret = 0;
  for (int x = pos; x > 0; x &= x - 1) ret += bit[x - 1];
  return ret;
}
template <class T> T bSum(const vector<T> &bit, int pos0, int pos1) {
  return bSum(bit, pos1) - bSum(bit, pos0);
}


int N, M;
vector<int> A, B;

vector<vector<int>> G;


namespace brute {
// 0: first, nigeru; 1: second, ou
int win[2][2010][2010];
int deg[2][2010][2010];
Int run() {
  vector<int> degTree(N, 0);
  for (int i = 0; i < N - 1; ++i) {
    ++degTree[A[i]];
    ++degTree[B[i]];
  }
  memset(win, ~0, sizeof(win));
  memset(deg, 0, sizeof(deg));
  queue<pair<int, pair<int, int>>> que;
  for (int u = 0; u < N; ++u) for (int v = 0; v < N; ++v) {
    if (u == v) {
      for (int t = 0; t < 2; ++t) {
        win[t][u][v] = t;
        que.emplace(t, make_pair(u, v));
      }
    } else {
      deg[0][u][v] = 1 + (int)G[u].size();
      deg[1][u][v] = 1 + degTree[v];
    }
  }
  for (; !que.empty(); ) {
    const int t = que.front().first;
    const int u = que.front().second.first;
    const int v = que.front().second.second;
    que.pop();
    auto reach = [&](int tt, int uu, int vv) -> void {
      if (!~win[tt][uu][vv]) {
        if (win[t][u][v]) {
          if (!--deg[tt][uu][vv]) {
            win[tt][uu][vv] = 0;
            que.emplace(tt, make_pair(uu, vv));
          }
        } else {
          win[tt][uu][vv] = 1;
          que.emplace(tt, make_pair(uu, vv));
        }
      }
    };
    if (t) {
      // reverse nigeru
      reach(0, u, v);
      for (const int i : G[u]) {
        reach(0, A[i] ^ B[i] ^ u, v);
      }
    } else {
      // reverse ou
      reach(1, u, v);
      for (const int i : G[v]) if (i < N - 1) {
        reach(1, u, A[i] ^ B[i] ^ v);
      }
    }
  }
// for(int t=0;t<2;++t)for(int u=0;u<N;++u){cerr<<"win["<<t<<"]["<<u<<"] = ";pv(win[t][u],win[t][u]+N);}
  Int ans = 0;
  for (int u = 0; u < N; ++u) for (int v = 0; v < N; ++v) if (u != v) {
    if (win[0][u][v]) {
      ++ans;
    }
  }
  return ans;
}
}  // brute


namespace one {
vector<int> par;
void dfs(int u, int p) {
  par[u] = p;
  for (const int i : G[u]) if (i < N - 1) {
    const int v = A[i] ^ B[i] ^ u;
    if (p != v) {
      dfs(v, u);
    }
  }
}
vector<int> on;
vector<vector<int>> dss;
void DFS(int k, int u, int p, int d) {
  dss[k].push_back(d);
  for (const int i : G[u]) if (i < N - 1) {
    const int v = A[i] ^ B[i] ^ u;
    if (p != v && !on[v]) {
      DFS(k, v, u, d + 1);
    }
  }
}
Int run() {
  const int s = A[N - 1];
  const int t = B[N - 1];
  par.assign(N, -1);
  dfs(s, -1);
  vector<int> path;
  for (int u = t; ~u; u = par[u]) {
    path.push_back(u);
  }
  reverse(path.begin(), path.end());
  const int len = (int)path.size() - 1;
cerr<<"path = "<<path<<endl;
  Int ans = 0;
  if (len >= 3) {
    on.assign(N, 0);
    for (int k = 0; k <= len; ++k) {
      on[path[k]] = 1;
    }
    dss.assign(len + 1, {});
    for (int k = 0; k <= len; ++k) {
      DFS(k, path[k], -1, 0);
    }
    // go to s
    {
      vector<int> bit(N, 0);
      for (int k = 0; k <= len; ++k) {
        for (const int d : dss[k]) bAdd(bit, k + d, +1);
        for (const int d : dss[k]) ans += bSum(bit, k + d);
      }
    }
    // go to t
    {
      vector<int> bit(N, 0);
      for (int k = len; k >= 0; --k) {
        for (const int d : dss[k]) ans += bSum(bit, (len - k) + d);
        for (const int d : dss[k]) bAdd(bit, (len - k) + d, +1);
      }
    }
  }
  return ans;
}
}  // one


int main() {
  for (; ~scanf("%d%d", &N, &M); ) {
    M += (N - 1);
    A.resize(M);
    B.resize(M);
    for (int i = 0; i < M; ++i) {
      scanf("%d%d", &A[i], &B[i]);
      --A[i];
      --B[i];
    }
    
    G.assign(N, {});
    for (int i = 0; i < M; ++i) {
      G[A[i]].push_back(i);
      G[B[i]].push_back(i);
    }
    
    Int ans;
    if (M - (N - 1) == 1) {
      ans = one::run();
    } else {
      ans = brute::run();
    }
    printf("%lld\n", ans);
  }
  return 0;
}