import sys
sys.stdin = open('1238_contact_DFS.txt', 'r')

def DFS(start_node):
    visited[start_node] = 1

    for next_node in range(1, N+1):
        if MyMap[start_node][next_node] and not visited[next_node]:
            visited[next_node] = 1
            if Distance[next_node] == 0:
                Distance[next_node] = Distance[start_node] + 1
            elif Distance[next_node] != 0 and Distance[next_node] > Distance[start_node] + 1:
                Distance[next_node] = Distance[start_node] + 1
            DFS(next_node)
            visited[next_node] = 0

TC = 10
for tc in range(1, TC+1):
    Len, init_num = map(int, input().split())
    Data = list(map(int, input().split()))
    N = max(Data)
    MyMap = [[0]*(N+1) for _ in range(N+1)]

    for i in range(Len//2):
        start = Data[i*2]
        end = Data[(i*2)+1]
        MyMap[start][end] = 1

    Q = []
    Distance, visited = [0]*(N+1), [0]*(N+1)

    DFS(init_num)
    # print(Distance)

    max_D = Distance[0]
    for i in range(1, len(Distance)):
        if max_D <= Distance[i]:
            max_D = Distance[i]
            index = i

    print(f'#{tc} {index}')