#![allow(unused_imports)]
use std::cmp::*;
use std::collections::*;
use std::io::Write;
use std::ops::Bound::*;

#[allow(unused_macros)]
macro_rules! debug {
    ($($e:expr),*) => {
        #[cfg(debug_assertions)]
        $({
            let (e, mut err) = (stringify!($e), std::io::stderr());
            writeln!(err, "{} = {:?}", e, $e).unwrap()
        })*
    };
}

fn main() {
    let v = read_vec::<usize>();
    let (n, q) = (v[0], v[1]);
    let s = read::<String>().chars().collect::<Vec<_>>();
    let mut queries = vec![];
    for i in 0..q {
        let v = read_vec::<usize>();
        let (l, r, x) = (v[0] - 1, v[1] - 1, v[2] - 1);
        queries.push((l, r, x));
    }

    for (l, r, x) in queries {
        let mut count = vec![0; 26];
        for i in l..=r {
            count[s[i].to_digit(36).unwrap() as usize - 10] += 1;
        }
        let mut x = x;
        for ci in 0..26 {
            if x < count[ci] {
                println!("{}", std::char::from_digit(ci as u32 + 10, 36).unwrap());
                break;
            }
            x -= count[ci];
        }
    }
}

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}