#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <unordered_map>

using namespace std;


int palindromeSubStrs(string s)
{
    map<string, int> m;
    int n = s.size();
 
    // table for storing results (2 rows for odd-
    // and even-length palindromes
    int R[2][n+1];
 
    // Find all sub-string palindromes from the given input
    // string insert 'guards' to iterate easily over s
    s = "@" + s + "#";
 
    for (int j = 0; j <= 1; j++)
    {
        int rp = 0;   // length of 'palindrome radius'
        R[j][0] = 0;
 
        int i = 1;
        while (i <= n)
        {
            //  Attempt to expand palindrome centered at i
            while (s[i - rp - 1] == s[i + j + rp])
                rp++;  // Incrementing the length of palindromic
                       // radius as and when we find vaid palindrome
 
            // Assigning the found palindromic length to odd/even
            // length array
            R[j][i] = rp;
            int k = 1;
            while ((R[j][i - k] != rp - k) && (k < rp))
            {
                R[j][i + k] = min(R[j][i - k],rp - k);
                k++;
            }
            rp = max(rp - k,0);
            i += k;
        }
    }
 
    // remove 'guards'
    s = s.substr(1, n);
 
    // Put all obtained palindromes in a hash map to
    // find only distinct palindromess
    m[string(1, s[0])]=1;
    for (int i = 1; i <= n; i++)
    {
        for (int j = 0; j <= 1; j++)
            for (int rp = R[j][i]; rp > 0; rp--)
               m[s.substr(i - rp - 1, 2 * rp + j)]=1;
        m[string(1, s[i])]=1;
    }
    
    return m.size()-1;
}


int main(){
    int n;
    int q;
    cin >> n >> q;
    string s;
    cin >> s;
    for(int a0 = 0; a0 < q; a0++){
        // your code goes here
        int l,a,b,c,k,j=0;
        cin>>l>>a>>b>>c;
        string s1;
        if(l==1)
            {
            for( k=a;k<=b;++k){
            s[k]=s[k]+c;
                }
        }
        if(l==2)
            {
            for(int i=a;i<=b;++i)
                {
                s1[j]=s[i];
                j++;
            }
            cout<<palindromeSubStrs(s1)<<endl;
        }
    }
    return 0;
}