from itertools import repeat
from functools import reduce
from collections import Counter
import operator

prod = lambda x: reduce(operator.mul, x, 1)

def shift(c, k):
    return chr((ord(c)-ord('a') + k) % 26 + ord('a'))

def q1(s, i, j, k):
    return s[:i] + ''.join(map(shift, s[i:j+1], repeat(k))) + s[j+1:]

n,q = input().strip().split(' ')
n,q = [int(n),int(q)]
s = input().strip()
for a0 in range(q):
    query = input().strip()
    if query[0] == '1':
        s = q1(s, *map(int, query[2:].split()))
    if query[0] == '2':
        i,j = map(int, query[2:].split())
        d = Counter(s[i:j+1])
        a = d.values()
        p = sum(a)# + prod(map(lambda x: x//2 if x >= 2 else 1, a))
        ans = p
        print(ans)