import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int q = in.nextInt();
        String s = in.next();       
        for(int a0 = 0; a0 < q; a0++){
            int t = in.nextInt();
            if(t == 1) {
                int i = in.nextInt();
                int j = in.nextInt();
                int z = in.nextInt();
                 char a[] = s.toCharArray();
                for(int x = i; x <= j; x++) 
                   a[x]+=z;
                s = new String(a);
                //System.out.println(s);
            }
            else {
                int i = in.nextInt();
                int j = in.nextInt();
                int count = (j-i)+1;
                for(int x = i; x <= j; x++){
                    for(int y = x+1; y <= j; y++) {
                        if(isPal(s, i, x, y))
                            count++;
                    }
                }
                System.out.println(count);
            }
        }
    }
    
    public static boolean isPal(String s, int i, int x, int y) {
        String sub = s.substring(i, x+1) + "" + s.charAt(y);
        //System.out.println(sub);
        String rev = "";
        for(int j = sub.length()-1; j >= 0; j--)
            rev += sub.charAt(j);
        if(sub.equals(rev))
           return true;
        return false;
    }
}