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