Imports System

Public Class Test
	Public Shared Sub Main()
        Dim s() As String
        s = Split(Console.ReadLine())
        Dim x, y, z As Integer
        Dim n As Integer
        x = s(0)
        y = s(1)
        z = s(2)
        n = (x - z) \ (y + z)
        Console.WriteLine(n)
	End Sub
End Class