How to initialize structure with compiler generated backing fields

How to initialize structure with compiler generated backing fields

Ultra simple question... How does one properly initialize private backing
fields on a structure? I get a compiler error:
Backing field for automatically implemented property 'Rectangle.Y' must be
fully assigned before control is returned to the caller. Consider calling
the default constructor from a constructor initializer.
Heres the source code.
public struct Rectangle
{
public Rectangle(int x, int y, int width, int height)
{
X = x;
Y = y;
Width = width;
Height = height;
}
public int Width { get; private set; }
public int Height { get; private set; }
public int X { get; private set; }
public int Y { get; private set; }
}