fun main() {
    val (n, q) = readLine()!!.split(" ").map{it.toInt()}
    val s = readLine()!!
    val sum = Array(26){IntArray(n+1)}
    for(i in s.indices){
        sum[s[i]-'a'][i+1]++
    }
    for(i in 0 until 26){
        for(j in 1..n){
            sum[i][j] += sum[i][j-1]
        }
    }
    repeat(q){
        val (l, r, x) = readLine()!!.split(" ").map{it.toInt()}
        var acc = 0
        for(i in 0 until 26){
            acc += sum[i][r]-sum[i][l-1]
            if(acc >= x){
                println('a'+i)
                break
            }
        }
    }
}