#include <iostream>

using namespace std;

void f1(int a[100][100], int n)
{
    int i, j;
    for (i = 1; i <= n; i++)
    {
        cout << i << ": ";
        for (j = 1; j <= n; j++)
            if (a[i][j] == 1)
                cout << j << " ";
        cout << endl;
    }
}

int f2(int a[100][100], int n, v[100])
{
    int i, j, ok = 0, pi, pf;
    // for (i = 1; i <= n; i++)
    //     for (j = 1; j <= n; j++)
    //         if (a[i][j] == 1)
    for (i = 2; i <= n; i++)
        if (a[v[i]][v[i - 1]] == 0)
        {
            if (ok == 0)
            {
                pi = i;
                pf = n;
            }
            ok++;
        }
    if (ok == 0)
    {
        for (i = 1; i <= n; i++)
            if (v[i] != v[n])
                return 0;
        return 1;
    }
    else
        return 0;
}

int a[100][100];

int main()
{
    int n, i, m, x, y;
    cin >> n >> m;
    for (i = 1; i <= m; i++)
    {
        cin >> x >> y;
        a[x][y] = a[y][x] = 1;
    }
    f2(a, n);

    return 0;
}