Problem from Lisic

“Zakhar_lutii,” said Lisic, can you write a program that will reproduce my masterpiece painting, which name is “Snails after the rain?”. Help Zakhar_lutii cope with the task, namely: for a given positive integer n print an image that has n lines and 2 * n - 1 columns formed by the snail '@' characters and the ':' character, as shown in the example.

Input

One positive integer n (n > 1).

Output

Print the image n * (2 * n - 1).

Examples