calculate the current through two nMOS transistors in series

Using the parameters given below, calculate the current through two nMOS transistors in series (see figure), when the drain of the top transistor is tied to VDD =1 V, the source of the bottom transistor is tied to Vss = 0 and their gates are tied to VDD. The substrate is also tied to Vss= 0V. Assume that W/L = 10 for both transistors.

k'= 170 μA/V2

VT0 = 0.45 V

γ = 0.5 V1/2

|2ΦF| = 1.01 V

λ = 0

Hint: The solution requires several iterations, and the body effect on threshold voltage has to be taken into account. Start with the KCL equation.