You want to make a rectangle that is 63 centimeters (cm) wide by 42 centimeters (cm) tall by joining several squares together without overlapping them. To minimize the number of squares, find how many centimeters (cm) each side of the square must be.
63 42 [OP_GCD]
var_a = 63
var_b = 42
var_c = math.gcd(int(var_b), int(var_a))
print(int(var_c))