def Ex_Euclid(a, b): if 0 == b: x = 1 y = 0 q = a return x, y, q xyq = Ex_Euclid(b, a % b) x = xyq[0] y = xyq[1] q = xyq[2] temp = x x = y y = temp-a//b*y return x, y, q def inv(a, b): return Ex_Euclid(a, b)[0] def gcd(a...