I have already taken RPI 3 B + from post office and now I want start RPI 3 B +. But I'm seeing that I haven't got 5V 2.5A Power Block. So, I have a question. Can I give power 5V 2.1A to Raspberry Pi 3 B +? Please, help me and say can I do it? Best Regards, Mammadli Elnur.