from collections import deque


def check_connectivity(adj, n):
    vis = [False for _ in range(n)]
    def dfs(x):
        vis[x] = True
        for v in adj[x]:
            if not vis[v]:
                dfs(v)
    dfs(0)
    return all(vis)


def check_cthulhu(adj, degree, n):
    marked = [False for _ in range(n)]
    dq = deque([])
    for i, d in enumerate(degree):
        if d == 1:
            dq.append(i)
            marked[i] = True

    while len(dq) != 0:
        i = dq.popleft()
        for v in adj[i]:
            if not marked[v]:
                degree[v] -= 1
                if degree[v] == 1:
                    dq.append(v)
                    marked[v] = True

    # if all are marked it means that there was no cycle
    if all(marked):
        return False

    # if some of the non-marked vertices does not have degree 2, it is not a simple cycle    
    for v in range(n):
        if not marked[v] and degree[v] != 2:
            return False

    return True


n, m = map(int, input().split())
adj = [[] for _ in range(n)]
degree = [0] * n

for i in range(m):
    u, v = map(int, input().split())
    u -= 1
    v -= 1
    adj[u].append(v)
    adj[v].append(u)
    degree[u] += 1
    degree[v] += 1

if not check_connectivity(adj, n) or not check_cthulhu(adj, degree, n):
    print("OFFLINE")
else:
    print("ONLINE")