dp = 21.times.map{ 11.times.map{ [0] * 156 } }

cnt = 1
(1..20).each do |n|
  cnt.downto(1).each do |j|
    (1..155).each do |k|
      dp[n][j][k] += dp[n - 1][j][k]
      dp[n][j][n + k] += dp[n - 1][j - 1][k] if n + k <= 155
    end
  end
  dp[n][1][n] = 1
  cnt += 1 if cnt < 10
end
 
loop do
  n, k, s = gets.split.map(&:to_i)
  break if n == 0
  p dp[n][k][s]
end