let cnt = Array.zeroCreate<int> 1010000
let mutable flg = false

let n = stdin.ReadLine() |> int

for i = 1 to n do
    let [| a; b|] =
        stdin.ReadLine().Split()
        |> Array.map int
    let x = a * 1000 + b
    cnt.[x] <- cnt.[x] + 1
    if not flg && cnt.[x] >= 2 then
        flg <- true

if flg then "Yes"
else "No"
|> printfn "%s"