local ior = io.read
local n = ior("*n")
local t = {}
for i = 1, n do t[i] = 0 end
local z = 2 * n - 2
local a = 0
for i = 1, z do
  a = ior("*n")
  t[a] = t[a] + 1
end
local cnt = 0
for i = 1, n do
  if(t[i] == 1) then cnt = cnt + 1 end
end
print(cnt - 2)