You can install the VS2013 toolset from your VS2015 installer without installing Visual Studio 2013.
From the 2015 installer, select "Windows 8.1 and Windows Phone 8.0/8.1 Tools" and "Common Tools for Visual C++ 2015":
After the installation has completed, you will find the platform Toolset below:
You should now be able to build your project with the platform toolset for Visual Studio 2013 (v120).
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…