Answer: $6,7,8 \| 6 ; 7 ; 8$
2. Given a quadrilateral $A B C D$. It is known that $B C=4, B D=9, A C=5, A D=3$. It is also known that at least one of the two unknown sides of the quadrilateral $A B C D$ is also an integer. Find what it can be equal to. In your answer, list all suitable values in ascending order separated by a semicolon.