Given a=23⋅52a = 2^3 \cdot 5^2a=23⋅52 and b=22⋅32⋅51b = 2^2 \cdot 3^2 \cdot 5^1b=22⋅32⋅51, find GCD(a,b)\text{GCD}(a, b)GCD(a,b).
202020
404040
101010
222