import sys

N, M, F, T, S = list(map(int, input().split(' ')))


LRAPT = S
TIGER = T

T_states = {TIGER}
L_states = {LRAPT}

vilage_conns = [list() for _ in range(N)]

for i in range(M):
  f, t = set(map(int, input().split(' ')))

  vilage_conns[f].append(t)
  vilage_conns[t].append(f)

j = 0
while F not in L_states:
  state_T = set()
  state_L = set()
  for i in T_states:
    state_T.update(vilage_conns[i])
  
  for i in L_states:
    state_L.update(vilage_conns[i])
  L_states = state_L
  T_states = state_T
  for i in L_states:
    if i in T_states:
      print("death")
      sys.exit(0)
  j += 1

print(j)