Find the output voltage of the circuit shown in the figure b

Find the output voltage of the circuit shown in the figure below. Diode voltage is 0.7V and v_1 = 3V.

Actually clearly observe that the circuit has only two known things that is input voltage is 3 volts and diode voltage 0.7 volts. Here we want output voltage is Vo(t) is the combination of diode voltage 0.7 and output battery E.

i.e. Vo(t)= diode voltage+ battery voltage