local n = io.read("*n")
local edge = {}
for i = 1, n do
  edge[i] = {}
end
for i = 1, n - 1 do
  local a, b = io.read("*n", "*n")
  table.insert(edge[a], b)
  table.insert(edge[b], a)
end
local c = 0
for i = 1, n do
  if 3 <= #edge[i] then
    if c == 0 then
      c = i
    else
      print("No") os.exit()
    end
  end
end
if c == 0 then print("Yes") os.exit() end
local len = {}
for i = 1, n do
  len[i] = -1
end
len[c] = 0
local tasks = {c}
for i = 1, n do
  local src = tasks[i]
  for j = 1, #edge[src] do
    local dst = edge[src][j]
    if len[dst] < 0 then
      len[dst] = len[src] + 1
      table.insert(tasks, dst)
    end
  end
end
local z = 0
for i = 1, n do
  if 1 == #edge[i] then
    if z == 0 then
      z = len[i]
    elseif z ~= len[i] then
      print("No") os.exit()
    end
  end
end
print("Yes")