#include <bits/stdc++.h>
#define fo(i,n) for(i=0;i<n;++i)
#define forr(i,n) for(i=n-1;i>0;--i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> ii;
typedef vector<ii> vii;
typedef vector<int> vi;
#define mod 1000000007

ll gcd(ll a,ll b){while(a&&b)a>b?a%=b:b%=a;return a+b;}
ll lcm(ll a,ll b){return a/gcd(a,b)*b;}

ll counter;
char c[100001];

void calc(int l, int r){
    vector<string>m;
    string s;
    for(int i=l;i<=r;i++)
        s = s + c[i];
    int n = s.length();
    int R[2][n+1];
    s = "@" + s + "#";

    for(int j = 0; j <= 1 ; j++){
        int rp = 0;
        R[j][0] = 0;
        int i = 1;
        while(i<=n){
            while(s[i-rp-1]==s[i+j+rp])
                rp++;
            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;
        }
    }
    s = s.substr(1,n);
    m.push_back(string(1,s[0]));
    for(int i = 1; i<=n ; i++){
        for(int j = 0; j<=1; j++){
            for(int rp= R[j][i]; rp>0;rp--)
                m.push_back(s.substr(i-rp-1,2*rp+j));
            m.push_back(string(1,s[i]));
        }
    }
    for(int i = 0;i<m.size();i++){
        cout<<m[i]<<endl;
    }
}

int main(){
    int k, h, n, m, x, l, r, t;
    cin>>n>>m;
    int i, j;
    fo(i,n)
        cin>>c[i];
    fo(j,m){
        cin>>x;
        if(x==1){
            cin>>l>>r>>t;
            for(i=l;i<=r;i++){
                t = t % 26;
                int shift = int(c[i])+t;
                if(shift > 122)
                    shift -= 26;
                c[i] = char(shift);
            }
        }
        else{
            cin>>l>>r;
            //calc(l,r);
            cout<<r-l+1<<endl;
        }
    }
    return 0;
}