For a circuit, you need to control two LEDs, but unfortunately, only one digital output is free. The supply voltage of the microcontroller and the board is $5~\rm V$. LED1 should have a forward voltage $U_{\rm f,1}=2.3~\rm V$ (red), LED2 should have a forward voltage $U_{\rm f,2}=2.1~\rm V$ (green).

1. Design a circuit from the existing voltage levels so that both LEDs can be driven.
   Existing voltage levels:
   1. Supply: $5~\rm V$
   2. Digital output: $5~\rm V$, $0~\rm V$ or high impedance

1. Calculate the values for the other necessary components

   
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