Imports System

Module Program
    Sub Main(args As String())
		Dim tmpA As String() = Split(Console.ReadLine(), " ")

		If tmpA(0) = tmpA(1) Then
			If tmpA(1) = tmpA(2) Then
				Console.WriteLine("NO")
				Exit Sub
			End If
		End If

		If tmpA(0) <> tmpA(1) Then
			If tmpA(1) <> tmpA(2) Then
				If tmpA(0) <> tmpA(2) Then
					Console.WriteLine("NO")
					Exit Sub
				End If
			End If
		End If

		Console.WriteLine("YES")


	End Sub
End Module
