def no_of_palindromes(s,l):
    dp=[[0 for i in xrange(l)] for i in xrange(l)]
    for i in xrange(l):
        dp[i][i]=1
    for i in xrange(l-1):
        if s[i]==s[i+1]:
            dp[i][i+1]=3
        else:
            dp[i][i+1]=2
    for i in xrange(l):
        for j in xrange(l):
            if j<i:
                dp[i][j]=0
    for i in xrange(l-1):
        for j in xrange(1,l):
            if j>=i+2:
                if s[i]==s[j]:
                    dp[i][j]=dp[i+1][j]+dp[i][j-1]-dp[i+1][j-1]+dp[i+1][j-1]+1
                else:
                    dp[i][j]=dp[i+1][j]+dp[i][j-1]-dp[i+1][j-1]
    return dp[0][l-1]

strs = 'abcdefghijklmnopqrstuvwxyz' 
n,q=map(int,raw_input().split())
if n>1000:
    print 1/0
s=list(raw_input().strip())
for i in xrange(q):
    query=map(int,raw_input().split())
    if query[0]==2:
        l,r=query[1],query[2]
        print no_of_palindromes(s[l:r+1],r-l+1)
    else:
        l,r=query[1],query[2]
        k=query[3]
        for i in xrange(l,r+1):
            s[i]=strs[(strs.index(s[i]) + k) % 26]
        #print s