import java.io.*; import java.util.*; public class Main { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = sc.nextInt(); int q = sc.nextInt(); char[] values = sc.next().toCharArray(); int[][] sums = new int[n + 1][26]; for (int i = 1; i <= n; i++) { for (int j = 0; j < 26; j++) { sums[i][j] = sums[i - 1][j]; } sums[i][values[i - 1] - 'a']++; } StringBuilder sb = new StringBuilder(); while (q-- > 0) { int left = sc.nextInt() - 1; int right = sc.nextInt(); int x = sc.nextInt(); int count = 0; for (int i = 0; i < 26; i++) { count += sums[right][i] - sums[left][i]; if (count >= x) { sb.append((char)(i + 'a')).append("\n"); break; } } } System.out.print(sb); } } class Scanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); public Scanner() throws Exception { } public int nextInt() throws Exception { return Integer.parseInt(next()); } public long nextLong() throws Exception { return Long.parseLong(next()); } public double nextDouble() throws Exception { return Double.parseDouble(next()); } public String next() throws Exception { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }