RU-SPB 2021 Problem 93

Given is cyclic quadrilateral $ABCD$ with∠ $A = 3$ ∠ $B$ . On the $AB$ side is chosen point $C_1$ , and on side $BC$ - point $A_1$ so that $AA_1 = AC = CC_1$ . Prove that $3A_1C_1>BD$ .