d={}

def palin(s,n):
    if (s,n) in d:  return d[(s,n)]
    #print(s,n)
    if n<0:         return 0
    if n==0:        return 1
    l=len(s)
    if l==0:        return 0
    k=1
    for x in range(n):
        if s[x]==s[n]:
            k+=(1+palin(s[x+1:n],n-x-2))            
    ret=palin(s,n-1)+k
    d[(s,n)]=ret
    #print(s,n,ret)
    return ret

[n,q]=[int(x) for x in input().strip().split(' ')]
s=list(input().strip())
for x in range(q):
    qu=[int(y) for y in input().strip().split(' ')]
    if qu[0]==1:
        for y in range(qu[1],qu[2]+1):
            s[y]=chr(((ord(s[y])-ord('a')+qu[3])%26)+ord('a'))
    else:
        ss=s[qu[1]:(qu[2]+1)]
        print(palin(''.join(ss),len(ss)-1))