N, Q = gets.split.map(&:to_i)
S = gets.chomp
counter = Array.new(N + 1) { Array.new(26, 0) }

N.times do |i|
  v = S[i].ord - 'a'.ord

  26.times do |j|
    counter[i + 1][j] = counter[i][j]
  end

  counter[i + 1][v] += 1
end

v = Array.new(26, 0)

Q.times do
  l, r, x = gets.split.map(&:to_i)

  26.times do |i|
    v[i] = counter[r][i] - counter[l - 1][i]
  end

  1.upto(25) do |i|
    v[i] += v[i - 1]
  end

  idx = v.bsearch_index { |c| c >= x }
  puts (idx + 97).chr
end