Public Class Program
  Shared Sub Main()
    Dim abc As Long() = Array.ConvertAll(Of String, Long)(Console.ReadLine().Split(" "), AddressOf Long.Parse)
    Dim a As Long = abc(0)
    Dim b As Long = abc(1)
    Dim c As Long = abc(2)
    Dim output As Long = c - (a - b)
    If output < 0 Then output = 0
    Console.WriteLine(output.ToString())
  End Sub
End Class