def f(xs)
	res=[]
	e=xs.shift
	while xs.empty? == false
		e2=e+xs[0]
		e2=e2%10+1 if(e2>=10)
		res<<e2
		e=xs.shift
	end
	return res
end
gets.to_i.times{
	xs=gets.chomp.split("").map{|e| e.to_i}
	while xs.size>1
		xs=f(xs)
	end
	p xs[0]
}