DouKaku?

b = gets.to_i
if b < 10**3
    puts b
elsif b < 10**6
    puts "%.1fk" % (b.to_f/10**3)
elsif b < 10**9
    puts "%.1fM" % (b.to_f/10**6)
elsif b < 10**12
    puts "%.1fG" % (b.to_f/10**9)
else
    puts "%.1fT" % (b.to_f/10**12)
end

select substring(c from 1 for l%3)||'.'||substring(c from l%3+1 for 1)||substring(' kMGTPE' from l/3+1 for 1)from(select column1 as c,length(column1)as l from(values('12345'))s)s;