#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

/*int countPS(string str)
{
    int N = str.length();
 
    // create a 2D array to store the count of palindromic
    // subsequence
    int cps[N+1][N+1];
    memset(cps, 0 ,sizeof(cps));
 
    // palindromic subsequence of length 1
    for (int i=0; i<N; i++)
        cps[i][i] = 1;
 
    // check subsequence of length L is palindrome or not
    for (int L=2; L<=N; L++)
    {
        for (int i=0; i<N; i++)
        {
            int k = L+i-1;
            if (str[i] == str[k])
                cps[i][k] = cps[i][k-1] +
                            cps[i+1][k] + 1;
            else
                cps[i][k] = cps[i][k-1] +
                            cps[i+1][k] -
                            cps[i+1][k-1];
        }
    }
 
    // return total palindromic subsequence
    return cps[0][N-1];
}*/
int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n;
    cin>>n;
    int t;
    cin>>t;
    string str;
        cin>>str;
    int N = n;
 
    // create a 2D array to store the count of palindromic
    // subsequence
    int cps[N+1][N+1];
for(int i=0;i<N;i++){
    for(int j=0;j<N;j++){
        cps[i][j]=0;
    }
}
 
    // palindromic subsequence of length 1
    for (int i=0; i<N; i++)
        cps[i][i] = 1;
 
    // check subsequence of length L is palindrome or not
    for (int L=2; L<=N; L++)
    {
        for (int i=0; i<N; i++)
        {
            int k = L+i-1;
            if (str[i] == str[k])
                cps[i][k] = cps[i][k-1] +
                            cps[i+1][k] + 1;
            else
                cps[i][k] = cps[i][k-1] +
                            cps[i+1][k] -
                            cps[i+1][k-1];
        }
    }
 
    while(t--){
        int num;
        cin>>num;
        if(num==1){
            int m,p,q;
            cin>>m>>p>>q;
            for(int i=m;i<=p;i++){
                if(str[i]+q>'z'){ str[i]-=26;  }
                 str[i]+=q;
            }
            for (int i=0; i<N; i++)
             cps[i][i] = 1;
 
          for (int L=2; L<=N; L++)
            {
                for (int i=0; i<N; i++)
                {
                    int k = L+i-1;
                    if (str[i] == str[k])
                        cps[i][k] = cps[i][k-1] +
                                    cps[i+1][k] + 1;
                    else
                        cps[i][k] = cps[i][k-1] +
                                    cps[i+1][k] -
                                    cps[i+1][k-1];
                }
            }
        }
        else{
            int m,p;
            cin>>m>>p;
            cout<<cps[m][p]<<endl;
            
        }
        
    }
    return 0;
}