local n, m = io.read("*n", "*n")
local a = {}
local aidx = {}
for i = 1, n do
  a[i] = io.read("*n")
  aidx[i] = i
end
table.sort(aidx, function(x, y) return a[x] < a[y] end)
local edge = {}
for i = 1, n do
  edge[i] = {}
end
for i = 1, m do
  local x, y = io.read("*n", "*n")
  if a[x] < a[y] then
    table.insert(edge[x], y)
  elseif a[y] < a[x] then
    table.insert(edge[y], x)
  end
end
local flag = {}
for i = 1, n do
  flag[i] = false
end
local k = io.read("*n")
for i = 1, k do
  local z = io.read("*n")
  flag[z] = true
end
local ret = {}
for ia = 1, n do
  local i = aidx[ia]
  if flag[i] then
    table.insert(ret, i)
    for j = 1, #edge[i] do
      local dst = edge[i][j]
      flag[dst] = not flag[dst]
    end
  end
end
print(#ret)
print(table.concat(ret, "\n"))