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 l = 0;l < q; l++){
            int a = in.nextInt();
            if(a == 1){
                int x = in.nextInt();
                int y = in.nextInt();
                int z = in.nextInt();
                String e = "";
                String a1 = s.substring(0,x);
                String a2 = s.substring(y+1);
                for(int i = x; i<=y;i++){
                    char g = s.charAt(i);
                    int b = z%26;
                    char u = (char)((int)g + b);
                    e += u;
                   
                }
                
                s = a1 + e+a2;
                
            }else if(a == 2){
                int j = in.nextInt();
                int k = in.nextInt();
                
                String s1 = s.substring(j,k+1);
                int ans = call(s1);
                System.out.println(ans);
            }
            
        }
    }
    
    
    public static int call(String s1){
        int n = s1.length();
   
		int store[][] = new int[n+1][n+1];
        
		for(int i=0;i<=n;i++) {
			for(int j=0;j<=n;j++) {
				if(i==j) {
					store[i][j] = 1;
				} else{
					store[i][j] = 0;
				}
			}
		}
        
		for(int len=2;len<=n;len++) {
			for(int i=1;i<=n;i++) {
				int j=i+len-1;
				if(j>n) continue;
				if(s1.charAt(i-1) == s1.charAt(j-1)) {
					store[i][j] = store[i][j-1]+store[i+1][j]+1;
				} else {
					store[i][j] = store[i][j-1]+store[i+1][j]-store[i+1][j-1];				
				}
			}
		}
		return store[1][n];
        
    }
}