Concatenate two lines

Two strings are given on two separate lines. Write a program that concatenates them in order and prints the result on one line.

Do not insert a space or any other character between them.

The first line contains the string $A$.

The second line contains the string $B$.

Aside from the trailing newline of each line, the line contents are part of the string.

Print the concatenation of $A$ and $B$ on one line.

Do not put a space or a newline between the two strings. The judge input always has two lines.