#!/bin/python3

import sys

def shift(c, t):
    return chr((ord(c)-ord('a')+t) % 26 + ord('a'))

def counts(a):
    ret = []
    for i in range(26):
        ret.append(len(list(filter( (lambda x:x==chr(97+i)), a))))
    return ret

def numPalindromes(s):
    m = dict()
    n = len(s)
 
    # table for storing results (2 rows for odd-
    # and even-length palindromes
    R = [[0 for x in range(n+1)] for x in range(2)]
 
    # Find all sub-string palindromes from the given input
    # string insert 'guards' to iterate easily over s
    s = "@" + s + "#"
 
    for j in range(2):
        rp = 0    # length of 'palindrome radius'
        R[j][0] = 0
 
        i = 1
        while i <= n:
 
            # Attempt to expand palindrome centered at i
            while s[i - rp - 1] == s[i + j + rp]:
                rp += 1 # Incrementing the length of palindromic
                        # radius as and when we find valid palindrome
 
            # Assigning the found palindromic length to odd/even
            # length array
            R[j][i] = rp
            k = 1
            while (R[j][i - k] != rp - k) and (k < rp):
                R[j][i+k] = min(R[j][i-k], rp - k)
                k += 1
            rp = max(rp - k, 0)
            i += k
 
    # remove guards
    s = s[1:len(s)-1]
 
    # Put all obtained palindromes in a hash map to
    # find only distinct palindrome
    m[s[0]] = 1
    k=1
    for i in range(1,n):
        for j in range(2):
            for rp in range(R[j][i],0,-1):
                m[s[i - rp - 1 : i - rp - 1 + 2 * rp + j]] = 1
                k+=1
        m[s[i]] = 1
        k+=1
 
    # printing all distinct palindromes from hash map
    return(k)
    

n,q = input().strip().split(' ')
n,q = [int(n),int(q)]
s = list(input().strip())

for a0 in range(q):
    cmd = input().strip().split(" ")
    
    if cmd[0] == "1":
        for i in range(int(cmd[1]), int(cmd[2])+1):
            s[i] = shift(s[i], int(cmd[3]))
    elif cmd[0] == "2":
        #print(''.join(s[int(cmd[1]):int(cmd[2])+1]))
        print(numPalindromes(''.join(s[int(cmd[1]):int(cmd[2])+1])))