#<27-.6>

#<27-.6>

from collections import deque
import sys

def main():
    data = sys.stdin.read().split()
    if not data:
        print(-1)
        return
    
    m = int(data[0])
    graph = [[] for _ in range(10)]  # 索引1-9使用
    index = 1
    
    # 构建无向图
    for _ in range(m):
        u = int(data[index])
        v = int(data[index+1])
        index += 2
        graph[u].append(v)
        graph[v].append(u)
    
    # 读取8个数字的初始位置
    p = list(map(int, data[index:index+8]))
    index += 8
    
    # 确定初始空顶点位置
    full_set = set(range(1, 10))
    used_set = set(p)
    empty_start = full_set.difference(used_set).pop()
    
    # BFS获取连通块
    component = set()
    queue_comp = deque([empty_start])
    visited_comp = set([empty_start])
    
    while queue_comp:
        node = queue_comp.popleft()
        component.add(node)
        for neighbor in graph[node]:
            if neighbor not in visited_comp:
                visited_comp.add(neighbor)
                queue_comp.append(neighbor)
    
    # 检查连通性条件
    if 9 not in component:
        print(-1)
        return
    
    for i in range(1, 9):
        start_pos = p[i-1]
        if start_pos != i and (start_pos not in component or i not in component):
            print(-1)
            return
    
    # 构建初始状态
    state = [0] * 9
    for num in range(1, 9):
        pos = p[num-1]
        state[pos-1] = num
    start_state = tuple(state)
    start_empty_index = empty_start - 1
    
    # 目标状态
    target = (1, 2, 3, 4, 5, 6, 7, 8, 0)
    
    # BFS搜索最小步数
    queue = deque()
    queue.append((start_state, start_empty_index, 0))
    visited = {start_state}
    
    while queue:
        state, empty_idx, steps = queue.popleft()
        if state == target:
            print(steps)
            return
        
        empty_vertex = empty_idx + 1  # 当前空顶点编号
        for neighbor in graph[empty_vertex]:
            nb_idx = neighbor - 1  # 邻接点索引
            if state[nb_idx] == 0:  # 跳过空顶点
                continue
                
            new_state = list(state)
            # 移动数字到空顶点位置
            new_state[empty_idx] = state[nb_idx]
            new_state[nb_idx] = 0
            new_state_tup = tuple(new_state)
            
            if new_state_tup not in visited:
                visited.add(new_state_tup)
                queue.append((new_state_tup, nb_idx, steps + 1))
    
    print(-1)

if __name__ == "__main__":
    main()