End-to-end encryption and privacy controls.
Message and call for free* around the world.
Group conversations made simple.
Say it with stickers, voice, GIFs and more.
Reach your customers from anywhere.
http://graphic.farafile.ir/file/44955/جزوه-درسی-و-کنکوری-فصل-دوم-گسسته-پایه-دوازدهم-گراف-و-مدلسازی