Draw squares with Obama (Lua)

subject

President Barack Obama is not only calling on everyone to learn to program , Even code by example , Became the first president in American history to write computer code .2014 end of the year , To celebrate “ Computer science education week ” The official launch of , Obama wrote very simple computer code ： Draw a square on the screen . Now you can draw with him ！

Input format ：
Enter the length of the side of the square in one line N（3≤N≤21） And some kind of character that forms the side of a square C, Space between .

Output format ：
Output by given character C Square drawn . But notice that the row spacing is larger than the column spacing , So to make the result look more like a square , The number of rows we output is actually the number of columns 50%（ Round to the nearest whole ）.

sample input ：
10 a
sample output ：
aaaaaaaaaa
aaaaaaaaaa
aaaaaaaaaa
aaaaaaaaaa
aaaaaaaaaa

---

Code

local s = io.read()
local n, ch
for i = 1, #s do
    if s:sub(i,i) == " " then
        n, ch = s:sub(1, i - 1), s:sub(i+1)
        break
    end
end

ch = ch:rep(n)
for i = 1, n / 2 + 0.5 do
    print(ch)
end