#include<bits/stdc++.h>
using namespace std;

#define ll long long
#define mp make_pair
#define pb push_back
#define mod 1000000007

const int MAXM = 1e5+4;
#define MAXMM 1000
int a[MAXM],b[MAXM];
ll dp[MAXMM][MAXMM]; 

ll cps(string str) {
    int len = str.length();

    for(int l=0; l<=len; l++){
        for(int r=0; r<=len; r++){
            dp[l][r] = 0;
        }
    }

    for(int ss=1; ss<=len; ss++) {
        for(int l=0; l<=len-ss; l++) {
            int r = l + ss;
            ll c = dp[l+1][r];
            char ch = str[l];

            for (int sp=l; sp<r; sp++) {
                if (str[sp] == ch)
                    c += 1 + dp[l+1][sp];
            }

            dp[l][r] = c;
        }
    }
    return dp[0][len];
}

int main()
{
    int n,q,i,j,k,ch,l,r,t;
    cin>>n>>q;

    string s;
    cin>>s;

    while(q--)
    {
        cin>>ch;
        if(ch==1){
            cin>>l>>r>>t;
            for(i=l;i<=r;i++){
                s[i] = (s[i]-'a'+t)%26+'a';
            }
            // cout<<s<<endl;
        }else{
            string ss="";
            cin>>l>>r;
            for(i=l;i<=r;i++){
                ss+=s[i];
            }
            cout<<cps(ss)<<endl;
        }
    }
    return 0;
}