Kyselyt

q = ARGF.readline.to_i

q.times do
  a = ARGF.readline.to_i
  l, s, b = 0, 1, 0
  begin
    s += b
    b = 10**l * 9 * (l += 1)
  end until s+b > a
  a -= s
  puts (10**(l-1)+a/l).to_s[a % l]
end

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: ACCEPTED