open System
type Sol() =
    member this.Solve() = 
        
        let ar = Array.create 10 true
        let N = stdin.ReadLine() |> int
        for i = 0 to (N-1) do
            let S = stdin.ReadLine().Split()
            match S.[4] with 
            | "NO" -> 
             (
                 for j = 0 to 3 do
                     ar.[int S.[j]] <- false
             )
            | "YES" -> 
             (
                 for j = 0 to 9 do
                     if (j <> (int S.[0])) && (j <> (int S.[1])) && (j <> (int S.[2])) && (j <> (int S.[3])) then ar.[j] <- false
             )
        
        Array.findIndex (fun e -> e = true ) ar |> printfn "%d"
        
let mySol = new Sol()
mySol.Solve()