local n, m = io.read("*n", "*n")
local s, g = io.read("*n", "*n")
local edge, av, len = {}, {}, {}
for i = 1, n do
  edge[i] = {}
  av[i] = true
  len[i] = false
end
for i = 1, m do
  local a, b = io.read("*n", "*n")
  table.insert(edge[a], b)
  table.insert(edge[b], a)
end
local u = io.read("*n")
for i = 1, u do
  local z = io.read("*n")
  av[z] = false
end
len[s] = true
local done = 0
local tasks = {s}
while done < #tasks do
  done = done + 1
  local src = tasks[done]
  for j = 1, #edge[src] do
    local dst = edge[src][j]
    if av[dst] and not len[dst] then
      len[dst] = true
      table.insert(tasks, dst)
    end
  end
end
print(len[g] and "Yes" or "No")