package main
import "fmt"
type Rib struct {
  in, out int
}
var orgraph [][]int
var condel [][]int
var condribs [] Rib
type Vertex struct {
  time, comp, low int
}
var time, count, stak int
func VVTarjan(vertex []Vertex, num int, stack []int) {
  var prom Rib
  vertex[num].time, vertex[num].low, time = time, time, time+1
  stack[stak] = num
  stak++
  for i := 0; i < len(vertex); i++ {
    if orgraph[num][i] == 1 {
      if vertex[i].time == 0 {
        VVTarjan(vertex, i, stack)
      }
      if (vertex[i].comp == 0) && (vertex[num].low > vertex[i].low) {
	vertex[num].low = vertex[i].low
      }
      if vertex[i].comp != 0 {
	prom.in, prom.out = i, num
	condribs = append(condribs, prom)
      }
    }
  }
  j := 0
  if vertex[num].time == vertex[num].low {
    condel = append(condel, make([]int, 0))
A:  stak--
    j = stack[stak]
    condel[count-1] = append(condel[count-1], j)
    vertex[j].comp = count
    if j != num { goto A }
    count++
  }
}
func Tarjan(vertex []Vertex) int {
  time, count = 1, 1
  stack := make([]int, len(vertex))
  for i := 0; i < len(vertex); i++ {
    if vertex[i].time == 0 {
      VVTarjan(vertex, i, stack)
    }
  }
  res := 0
  for i := 0; i < len(vertex); i++ {
    if vertex[i].comp > res { res = vertex[i].comp }
  }
  return res
}
func inside(arr []int) bool {
  for i := 0; i < len(arr); i++ {
    if arr[i] == -1 { return false }
  }
  return true
}
func main() {
  var n, m int
  fmt.Scanf("%d %d", &n, &m)
  vertex := make([]Vertex, n)
  orgraph = make([][]int, n)
  condel = make([][]int, 0)
  for i := 0; i < n; i++ {
    orgraph[i] = make([]int, n)
  }
  var node1, node2 int
  for i := 0; i < m; i++ {
    fmt.Scanf("%d %d", &node1, &node2)
    orgraph[node1][node2] = 1
  }
  Tarjan(vertex)
  condrgaph := make([][]int, len(condel))
  for i := 0; i < len(condel); i++ {
    condrgaph[i] = make([]int, len(condel))
  }
  for i := 0; i < len(condribs); i++ {
    condrgaph[vertex[condribs[i].out].comp-1][vertex[condribs[i].in].comp-1] = 1
    condrgaph[vertex[condribs[i].in].comp-1][vertex[condribs[i].out].comp-1] = -1
  }
  for i := 0; i < len(condel); i++ {
    if inside(condrgaph[i]) {
      fmt.Printf("%d ", condel[i][len(condel[i])-1])
    }
  }
  fmt.Printf("\n")
}