int n, m;

cin >> n >> m;

for (int i=0; i<m; i++) {

int from, to;

cin >> from >> to;

edges.push_back({from, to});

edges.push_back({to, from});

a[from][to] = a[to][from] = true;

g[from].push_back(to);

g[to].push_back(from);

}

m *= 2;

for (int i=0; i<m; i++) {

for (int j=0; j<m; j++) {

// A -> B

int A = edges[i].first;

int B = edges[i].second;

// C -> D

int C = edges[j].first;

int D = edges[j].second;

if (A == B || A == C || A == D || B == C || B == D || C == D) {

continue;

}

// B -> C

if (!a[B][C]) {

continue;

}

// D -> E

for (int E : g[D]) {

if (A == E || B == E || C == E || D == E) {

continue;

}

cout << 1 << '\n';

return 0;

}

}

}

cout << 0 << '\n';

return 0;

}