let N = stdin.ReadLine() |> int
let A = stdin.ReadLine().Split(' ') |> Array.map int

let mutable count = 0
for i in N-1 .. -1 .. 0 do
    if A.[i] = N then
        let mutable find = N - 1
        let mutable tmpcount = 1
        for j in i-1 .. -1 .. 0 do
            if A.[j] = find then
                find <- A.[j] - 1
                tmpcount <- tmpcount + 1
        if tmpcount > count then count <- tmpcount

printfn "%d" <| N - count