#include <iostream>
#include <memory>
#include <algorithm>
#include <cstdio>

using namespace std;

int POSX[1024];
int POSY[1024];
int TABLE[1024][1024];

void Init(int m)
{
  memset(TABLE, 0, sizeof(TABLE));
  for (int i = 1; i <= m; ++i){
    POSX[i] = i;
    POSY[i] = 0;
    TABLE[i][0] = i;
  }
}

void Move(int x, int y, int xx, int yy)
{
  if (x == xx){
    cerr << "hoge" << endl;
    return;
  }
  int num = TABLE[x][y];
  //fprintf(stderr, "Move x:%d y:%d xx:%d yy:%d num:%d\n", x, y, xx, yy, num);
  TABLE[x][y] = 0;
  TABLE[xx][yy] = num;
  POSX[num] = xx;
  POSY[num] = yy;
}

void Move(int x, int y, int xx)
{
  //fprintf(stderr, "Move x:%d y:%d xx:%d\n", x, y, xx);
  //if (x == 0 || xx == 0){
    //cerr << "ERROR! Move(x, y, xx)" << endl;
  //}
  //if (TABLE[x][y] == x && y == 0){
    //cerr << "hugo" << endl;
    //return;
  //}
  for (int yy = 0; ; ++yy){
    if (TABLE[xx][yy] == 0){
      Move(x, y, xx, yy);
      return;
    }
  }
}

void Return(int x, int y)
{
  int yy = y;
  while (TABLE[x][y]){
    ++y;
  }
  --y;
  for (; y >= yy; --y){
    if (y == 0){
      break;
    }
    Move(x, y, TABLE[x][y]);
  }
}

void Take(int a, int b)
{
  int ax = POSX[a];
  int ay = POSY[a];
  int bx = POSX[b];
  int by = POSY[b];

  if (b == 0){
    if (ay == 0){
      return;
    }
    Return(ax, ay);
    return;
  }
  //fprintf(stderr, "Take %d %d  ax:%d ay:%d bx:%d by:%d\n", a, b ,ax, ay, bx, by);

  if (ax == bx){
    if (ay > by){
      return;
    }
    Return(ax, ay);

    ax = POSX[a];
    ay = POSY[a];
    bx = POSX[b];
    by = POSY[b];
  } else {
    if (TABLE[ax][ay + 1]){
      int x = ax;
      for (int y = ay + 1; TABLE[x][y]; ++y){
	Move(x, y, TABLE[x][y]);
      }
    }
  }

  Move(ax, ay, bx);
}

void PrintAnswer(int m)
{
  int answer[m];
  for (int i = 0; i < m; ++i){
    int x = i + 1;
    for (int y = 0; ; ++y){
      if (TABLE[x][y] == 0){
	answer[i] = y;
	break;
      }
    }
  }

  sort(answer, answer + m);

  for (int i = 0; i < m; ++i){
    if (answer[i]){
      cout << answer[i] << endl;
    }
  }
  cout << "end" << endl;
}

void PrintPile(int m)
{
  for (int x = 1; x <= m; ++x){
    cerr << x << ":";
    for (int y = 0; TABLE[x][y]; ++y){
      cerr << TABLE[x][y] << " ";
    }
    cerr << endl;
  }
}

main()
{
  int m;
  while (cin >> m && m){
    Init(m);

    int a, b;
    while (cin >> a >> b && (a || b)){
      if (a == b){
	continue;
      }
      Take(a, b);
      //PrintPile(m);
    }

    PrintAnswer(m);
  }
}