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();
            int right = sc.nextInt();
            int x = sc.nextInt();
            int count = 0;
            for (int i = 0; i < 26; i++) {
                count += sums[right][i] - sums[left - 1][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("");
    StringBuilder sb = new StringBuilder();
    
    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();
    }
    
}