let n = stdin.ReadLine () |> int
let a = stdin.ReadLine().Split " " |> Array.map int


if a.Length > 2 then
    [|
        for i in 0..a.Length-2 ->
            min a.[i] a.[i+1] |> int64
    |] |> Array.reduce (fun prev x -> prev * x % 998244353L)
else
    (Array.min a |> int64) % 998244353L
|> printfn "%d"

// let mutable arr = Array.replicate n [||]
// arr.[0] <- Array.replicate a.[0] 1L
// for i in 1..n-1 do
//     arr.[i] <- Array.replicate a.[i] ((Array.sum arr.[i-1].[0..a.[i]-1]) % 998244353L)
//     // printfn "%A" arr
//     
// Array.last arr |> Array.head |> printfn "%d"