#!/bin/python3

import sys

def shift(n, s):
    s = s % 26
    out = ord(n) + s
    if out > ord('z'):
        out -= 26
    return chr(out)

import operator as op
def ncr(n, r):
    r = min(r, n-r)
    if r == 0: return 1
    numer = reduce(op.mul, xrange(n, n-r, -1))
    denom = reduce(op.mul, xrange(1, r+1))
    return numer//denom

def calculate_pali(n):
    alpha = [0] * 26
    for i in range(len(n)):
        alpha[ord(n[i]) - ord('a')] += 1
    total = 0
    count = 0
    single = 0
    double = 0
    for i in range(26):
        if (alpha[i] > 0):
            count += 1
        if (alpha[i] == 1):
            single += 1
        elif (alpha[i] >= 2):
            double +=1
    for i in range(1, double+1):
        total += (single + (double - i) + 1) * ncr(double, i)
    total += count
    return total
    

n,q = input().strip().split(' ')
n,q = [int(n),int(q)]
s = input().strip()
for a0 in range(q):
    query = [int(x) for x in input().strip().split(' ')]
    if int(query[0]) == 1:
        q1, a, b, t = query
        for i in range(a, b+1):
            shift(s[i], t)
    else:
        q1, a, b = query
        subset = s[a: b+1]
        print(calculate_pali(subset))
        
    # your code goes here