#include <bits/stdc++.h>
 
using namespace std;
 
#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl;
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}
typedef long long ll;
#define int ll
 
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(int)(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
#define Sp(p) cout<<setprecision(25)<< fixed<<p<<endl;
//int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
//int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
vi dx = {1, 0, -1, 0}, dy = {0, 1, 0, -1};
vi dx2 = { 1,1,0,-1,-1,-1,0,1 }, dy2 = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
const ll MOD = 1000000007;
//const ll MOD = 998244353;
// #define mp make_pair
//#define endl '\n'
const int N = 400;
int n, m;
vi x, y;

vii u2idx(N);
vi idx(N);

bool solve(int u, int v) {
    //DEBUG(pii(u, v));
    bitset<N> alive;
    fill(idx.begin(), idx.begin() + n, 0);
    priority_queue<int> pq;

    vi temp = {u, v};
    for (int u: temp) {
        alive[u] = true;
        int i = idx[u];
        if (i < u2idx[u].size()) {
            int j = u2idx[u][i];
            pq.push(j);
            idx[u]++;
        }
    }

    while (pq.size() > 0) {
        int i = pq.top();
        pq.pop();
        //DEBUG(i);
        int u = x[i], v = y[i];
        if (alive[u] and alive[v]) return false;
        assert(alive[u] or alive[v]);

        vi temp = {u, v};
        for (int u: temp) {
            alive[u] = true;
            while (idx[u] < u2idx[u].size()) {
                int ni = idx[u];
                int j = u2idx[u][ni];
                if (j >= i) idx[u]++;
                else break;
            }
            if (idx[u] < u2idx[u].size()) {
                int j = u2idx[u][idx[u]];
                pq.push(j);
                idx[u]++;
            }

        }
    }
    return true;
}

signed main() {
    cin >> n >> m;
    x.resize(m); y.resize(m);

    set<pii> st;
    rep (i, m) {
        cin >> x[i] >> y[i];
        x[i]--; y[i]--;
        st.insert(pii(x[i], y[i]));
        u2idx[x[i]].push_back(i);
        u2idx[y[i]].push_back(i);
    }
    rep (i, n) reverse(all(u2idx[i]));

    int ans = 0;
    rep (i, n) {
        for (int j = i + 1; j < n; j++) {
            if (st.count(pii(i, j))) continue;
            ans += (int)solve(i, j);
        }
    }
    cout << ans << endl;
}

Measured memory_bytes: 7680