IMO 1986 LL MON55

Origin: MON

Problem

Given an integer n \geq2, determine all n-digit numbers M0 = a1a2 . . . an (ai ̸= 0, i = 1, 2, . . ., n) divisible by the numbers M1 = a2a3 . . . ana1, M2 = a3a4 . . . ana1a2, . . . , Mn−1 = ana1a2 . . . an−1.