#include <bits/stdc++.h>
using namespace std;
#define fileio() freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#define fastio() cin.tie(0), ios_base::sync_with_stdio(0)
#define pb push_back
#define endl "\n"
#define sp " "
#define pii pair<int, int>
#define st first
#define nd second
#define N 100005
#define int long long
const int modulo = 1e9 + 7;
vector<int> adj[N];
int dp[N][2][2];
int add(int a, int b)
{
if (a + b < modulo) return a + b;
return a + b - modulo;
}
int mul(int a, int b)
{
return (a * b) % modulo;
}
int subs(int a, int b)
{
if (a < b) return a - b + modulo;
return a - b;
}
int fe(int a, int b)
{
if (b == 0) return 1;
if (b % 2) return mul(a, fe(a, b - 1));
int tmp = fe(a, b / 2);
return mul(tmp, tmp);
}
int f(int i, int j, int turn)
{
int ans = 0;
if (turn == 0) ans = 1;
for (auto k : adj[i])
{
if (k == j) continue;
if (turn == 1) ans |= f(k, i, 1 - turn);
else ans &= f(k, i, 1 - turn);
}
return ans;
}
int32_t main()
{
//fileio();
fastio();
int n, d;
cin>>n>>d;
for (int i = 1; i <= n; i++)
{
int u, v;
cin>>u>>v;
adj[u].pb(v);
adj[v].pb(u);
adj[n + u].pb(n + v);
adj[n + v].pb(n + u);
}
int ans = 0;
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= n; j++)
{
adj[i].pb(n + j);
if (f(1, 0, 1)) ans++;
adj[i].pop_back();
}
}
cout<<ans<<endl;
cerr<<"time taken : "<<(float)clock() / CLOCKS_PER_SEC<<" seconds\n";
}
