    Module Atcorder2

        Sub Main(ByVal args() As String)

            Dim ReadWords As String = String.Empty
            Dim i As Integer = 0
            Dim Cnt As Integer = 0

            ReadWords = Console.ReadLine()

            For i = 0 To ReadWords.Length - 1
                If ReadWords(i) = "1" Then
                    Cnt += 1
                End If
            Next

            Console.WriteLine(Cnt)

        End Sub

    End Module