import java.io.*;
import java.util.*;
import java.util.function.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int q = sc.nextInt();
        char[] inputs = sc.next().toCharArray();
        int[][] counts = new int[n + 1][26];
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < 26; j++) {
                counts[i + 1][j] = counts[i][j];
            }
            counts[i + 1][inputs[i] - 'a']++;
        }
        String result = IntStream.range(0, q).mapToObj(i -> {
            int left = sc.nextInt();
            int right = sc.nextInt();
            int current = sc.nextInt();
            for (int j = 0; j < 26; j++) {
                current -= counts[right][j] - counts[left - 1][j];
                if (current <= 0) {
                    return String.valueOf((char)(j + 'a'));
                }
            }
            return "";
        }).collect(Collectors.joining("\n"));
        System.out.println(result);
    }
}
class Scanner {
    BufferedReader br;
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() {
        try {
            br = new BufferedReader(new InputStreamReader(System.in));
        } catch (Exception e) {
            
        }
    }
    
    public int nextInt() {
        return Integer.parseInt(next());
    }
    
    public long nextLong() {
        return Long.parseLong(next());
    }
    
    public double nextDouble() {
        return Double.parseDouble(next());
    }
    
    public String next() {
        try {
            while (!st.hasMoreTokens()) {
                st = new StringTokenizer(br.readLine());
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            return st.nextToken();
        }
    }
    
}