#include <fstream>

using namespace std;

ifstream fin ("mdrumurilor.in");
ofstream fout ("mdrumurilor.out");

bool A[NMAX][NMAX];
int n, m;
bool D[NMAX][NMAX];

void citire();
void initializare_m(bool X[NMAX][NMAX]);

int main()
{
    int i, j, k;
    citire();
    initializare_m(D);
    for (k = 1; i <= n; ++k)
        for (i = 1; i <= n; ++i)
            for (j = 1; j <= n; ++j)
                if (D[i][j] == 0)
                    D[i][j] = D[i][k] && D[k][j];
    return 0;
}

void citire()
{
    int i, x, y;
    fin >> n >> m;
    for(i = 1; i <= m; i++)
    {
        fin >> x >> y;
        A[x][y] = A[y][x] = 1;
    }
}

void initializare_m(bool X[NMAX][NMAX])
{
    int i, j;
    for (i = 1; i <= n; ++i)
        X[i][i] = 1;
    for (i = 1; i <= n; ++i)
        for (j = 1; j <= m; ++j)
            X[i][j] = A[i][j];
}