Create Street Grid

You are given two sets of street names: one for horizontal streets and one for vertical streets. Your task is to construct a grid where each cell is formed by concatenating the horizontal street name and the vertical street name with an underscore in between.

More formally, you are given two integers \( n \) and \( m \) representing the number of horizontal and vertical streets respectively. Then you are given a list of \( n \) horizontal street names and a list of \( m \) vertical street names. You need to create a grid \( grid \) of size \( n \times m \) where the element at position \( (i, j) \) is defined as:

[ grid[i][j] = \texttt{horizontal_names}[i] + "_" + \texttt{vertical_names}[j] ]

Your solution should read input from stdin and output to stdout.

inputFormat

The input is read from stdin in the following format:

n m
horizontal_name_1 horizontal_name_2 ... horizontal_name_n
vertical_name_1 vertical_name_2 ... vertical_name_m

Where:

• n and m are integers, representing the number of horizontal and vertical streets respectively.
• The next line contains n space-separated strings representing the horizontal street names.
• The following line contains m space-separated strings representing the vertical street names.

outputFormat

Output the constructed grid to stdout. Print each row of the grid on a new line with the street names separated by a single space.

name_1 name_2 ... name_m
...

## sample

3 3
elm oak pine
first second third

elm_first elm_second elm_third
oak_first oak_second oak_third
pine_first pine_second pine_third

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