#include<bits/stdc++.h>
using namespace std; 
#define ll long long int
#define si set<int>
#define vi vector<int>
#define vii vector<vi>
#define mii map<int,int>
#define pii pair<int,int>
#define pff pair<double,double>
#define myfor(i,n) for(int i=0;i<n;i++)
#define mxx 100001
#define mmm 999999
#define PI  3.141592653589793238463
#define minm -2.59807621135
#define p 1000000007
#define M 1000000001
#define IMX INT_MAX
#define IMN INT_MIN
#define pre 1e-10 
#define MAX_SIZE 5000
long long numFound[MAX_SIZE][MAX_SIZE];
long long countPalindromes(string str) {
    int len = str.length();
    for (int startPos=0; startPos<=len; startPos++)
        for (int endPos=0; endPos<=len; endPos++)
            numFound[startPos][endPos] = 0;

    for (int spanSize=1; spanSize<=len; spanSize++) {
        for (int startPos=0; startPos<=len-spanSize; startPos++) {
            int endPos = startPos + spanSize;
            long long count = numFound[startPos+1][endPos];   //if str[startPos] is not in the palindrome, this will be the count
            char ch = str[startPos];

            //if str[startPos] is in the palindrome, choose a matching character for the palindrome end
            for (int searchPos=startPos; searchPos<endPos; searchPos++) {
                if (str[searchPos] == ch)
                    count += 1 + numFound[startPos+1][searchPos];
            }

            numFound[startPos][endPos] = count;
        }
    }
    return numFound[0][len];
}
int main()
{
    clock_t tstart = clock();
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n,q;
    cin>>n>>q;
    string str;
    cin>>str;
    while(q--)
    {
        int type;
        cin>>type;
        if(type==2)
        {
            int a,b;
            cin>>a>>b;
            string st = str.substr(a,b-a+1);
           // st ="aa";
          //  cout<<st<<" ";
            int l1 = st.length();
            cout<<countPalindromes(st)<<"\n";
        }
        else
        {
            int a,b,t;
            cin>>a>>b>>t;
            for(int i=a;i<=b;i++)
            {
                int x = str[i];
                x -= 'a';
                x = (x+t)%26 +'a';
                str[i]=(char)x;
            }
        }
        //cout<<str<<"\n";
    }
  //cout<<"\n\nTotal Time Taken : "<<fixed<<(double)(-tstart + clock())/CLOCKS_PER_SEC<<"sec\n\n";
  return 0;
}