global cycle, cycle_begin, cycle_end
cycle = -1
cycle_begin = 0
cycle_end = 0

def dfs(s):
    global cycle, cycle_begin, cycle_end
    visited[s] = 1

    for i in range(len(g[s])):
        if visited[g[s][i]] == 0:
            parent[g[s][i]] = s
            dfs(g[s][i])
        elif visited[g[s][i]] == 1:
            cycle = 1
            cycle_begin = g[s][i]
            cycle_end = s


    visited[s] = 2



n, m = map(int, input().split(' '))

g = {}
for i in range(1, n+1):
    g[i] = []

for i in range(m):
    a, b = map(int, input().split(' '))
    g[a].append(b)

parent = [0] * (n+1)
visited = [0] * (n+1)
path = []

for i in range(1, n):
    if cycle == 1:
        break
    if visited[i] == 0:
        dfs(i)
if cycle == 1:
    print("YES")
    a = []
    while cycle_end != cycle_begin:
        a.append(str(cycle_end))
        cycle_end = parent[cycle_end]
    a.append(str(cycle_begin))
    a.reverse()
    print(' '.join(a))

else:
    print("NO")