// Copyright (C) 2017 __debug.

// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; version 3

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; If not, see <http://www.gnu.org/licenses/>.


#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/priority_queue.hpp>

#define x first
#define y second
#define MP std::make_pair
#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(), (x).end()
#define DEBUG(...) fprintf(stderr, __VA_ARGS__)
#ifdef __linux__
#define getchar getchar_unlocked
#define putchar putchar_unlocked
#endif

using std::pair;
using std::vector;
using std::string;

typedef long long LL;
typedef pair<int, int> Pii;

const int oo = 0x3f3f3f3f;

template<typename T> inline bool chkmax(T &a, T b) { return a < b ? a = b, true : false; }
template<typename T> inline bool chkmin(T &a, T b) { return b < a ? a = b, true : false; }
string procStatus()
{
    std::ifstream t("/proc/self/status");
    return string(std::istreambuf_iterator<char>(t), std::istreambuf_iterator<char>());
}
template<typename T> T read(T &x)
{
    int f = 1;
    char ch = getchar();
    for (; !isdigit(ch); ch = getchar())
        f = (ch == '-' ? -1 : 1);
    for (x = 0; isdigit(ch); ch = getchar())
        x = 10 * x + ch - '0';
    return x *= f;
}
template<typename T> void write(T x)
{
    if (x == 0) {
        putchar('0');
        return;
    }
    if (x < 0) {
        putchar('-');
        x = -x;
    }
    static char s[20];
    int top = 0;
    for (; x; x /= 10)
        s[++top] = x % 10 + '0';
    while (top)
        putchar(s[top--]);
}
// EOT

const int MAXN = 405, MAXM = 1e5 + 5;

int N, M;
vector<Pii> G[MAXN];

void input()
{
    read(N); read(M);
    for (int i = 1; i <= M; ++i) {
        int u, v;
        read(u); read(v);
        G[u].push_back(MP(v, i));
        G[v].push_back(MP(u, i));
    }
}

int del[MAXN][MAXN];
bool conflict[MAXN];

void solve()
{
    for (int s = 1; s <= N; ++s) {
        static int q[MAXN];
        int front = 0, rear = 0;
        del[s][s] = +oo;
        q[rear++] = s;
        while (front != rear) {
            int u = q[front++];
            for (int i = 0; i < SZ(G[u]); ++i) {
                int v = G[u][i].x, t = G[u][i].y;
                if (t < del[s][u]) {
                    if (!del[s][v]) {
                        del[s][v] = t;
                        q[rear++] = v;
                    } else if (del[s][v] != t) {
                        conflict[s] = true;
                        goto END;
                    }
                }
            }
        }
      END:;
    }

    int ans = 0;
    for (int i = 1; i <= N; ++i) {
        if (conflict[i]) continue;
        for (int j = i + 1; j <= N; ++j) {
            if (conflict[j]) continue;
            for (int k = 1; k <= N; ++k) {
                if (del[i][k] && del[j][k] && del[i][k] != del[j][k])
                    goto FAIL;
            }
            ++ans;
          FAIL:;
        }
    }

    printf("%d\n", ans);
}

int main()
{
#ifdef __DEBUG
    freopen("E.in", "r", stdin);
    freopen("E.out", "w", stdout);
#endif

    input();
    solve();

    return 0;
}

// 孰知不向边庭苦，纵死犹闻侠骨香。
//     -- 王维《少年行四首》


Measured memory_bytes: 3328