func main()
	var n: int :: cui@inputInt()
	var q: int :: cui@inputInt()
	var s: []char :: cui@input()
	var cum: [][]int :: #[26, n + 1]int
	for i(1, n)
		for j(0, 25)
			do cum[j][i] :: cum[j][i - 1]
		end for
		do cum[s[i - 1] $ int - 'a' $ int][i] :+ 1
	end for
	
	for(1, q)
		var l: int :: cui@inputInt()
		var r: int :: cui@inputInt()
		var x: int :: cui@inputInt()
		var num: int
		var ans: char
		for i(0, 25)
			do num :: cum[i][r] - cum[i][l - 1]
			do x :- num
			if(x <= 0)
				do ans :: 'a'.offset(i)
				break i
			end if
		end for
		do cui@print("\{ans}\n")
	end for
end func