#include<bits/stdc++.h>
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define FOR(i,a,b) for(i=a;i<b;++i)
#define FORD(i,a,b) for(i=a;i>=b;--i)
#define FORIT(it,a,b) for(it=a;it!=b;it++)
#define tpI(i,a,b,v) for(i=a;i<b;i++) { p(v[i]);} pn();
#define tpL(i,a,b,v) for(i=a;i<b;i++) { pl(v[i]);} pn();
#define ll long long
#define mp make_pair
#define pb push_back
#define MOD 1000000007
#define infi 1000000007
#define ss(x) scanf("%s",x)
#define s(x) scanf("%d", &x)
#define sl(x) scanf("%lld", &x)
#define sd(x) scanf("%lf", &x)
#define fi first
#define se second
#define p(x) printf("%d ",x)
#define pl(x) printf("%lld ", x)
#define pd(x) printf("%lf ", x)
#define pn() printf("\n")
#define pc() printf("test \n")
#define pm(m) printf("%s\n",m)
#define pmv(m,x) printf("%s  -->  %d\n",m,x)
using namespace std;

int cps[1000+1][1000+1];

void countPS(string str)
{
    int N = str.length();
 
    // create a 2D array to store the count of palindromic
    // subsequence
    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];
        }
    }
 }

string shift(string str,int start,int end,int t)
{
    int i,j,l=str.length();
    t=t%26;
    for(i=start;i<=end;i++)
    {
        str[i]=str[i]+t;
        if(str[i]>122)
            str[i]=str[i]-122+96;
    }
    return str;
}

int main()
{
    int n,q;
    cin>>n>>q;
    string str;
    cin>>str;
    int l = str.length(),last;
    countPS(str);
    while(q--)
    {
        int choice ;
        cin>>choice;
        if(choice==1)
        {
            int start,end,t;
            cin>>start>>end>>t;
            str=shift(str,start,end,t);
            last=1;
        }
        else 
        {
            int start,end;
            cin>>start>>end;
            if(last==1)
                countPS(str);
            cout<<cps[start][end]<<endl;
               last=2;
         
        }
    }
    
    return 0;
}