#include <cstdio>
#include <cstring>
#include <cmath>
#include <queue>
#include <cstring>
#include <vector>
#include <string>
#include <stack>
#include <set>
#include <map>
#include <iostream>
#include <algorithm>
using namespace std;
#define MP make_pair
#define PB push_back
typedef long long LL;
typedef pair<int, int> Pii;
const int inf = 0x3f3f3f3f;
const LL INF = (1uLL << 63) - 1;
const LL mod = 1000000007;
const double Pi = acos(-1.0);
const int maxn = 1e5 + 5;
#define mid (( l + r ) >> 1)
#define lson l,mid, o<<1
#define rson mid+1,r,o<<1|1
char s[505];
int dp[505][505];
int query(int l , int r){
    for(int i = l; i <= r; i++){
        dp[i][i] = 1;
        for(int j = i - 1; j >= l; j--){
            if(s[i]==s[j])dp[j][i] = dp[j+1][i] + dp[j][i-1] + 1;
            else dp[j][i] = dp[j+1][i] + dp[j][i-1] - dp[j+1][i-1];
        }
    }
    return dp[l][r];
}
void fix(int l,int r,int t){
    for(int i = l ;i <= r; i++){
        s[i] = (s[i] - 'a' + t )% 26 + 'a';
    }
}
int main() {
#ifdef local
    freopen("in", "r", stdin);
#endif
    ios::sync_with_stdio(false);
    int n,q;
    cin>>n>>q;
    cin>>s;
    for(int i = 0 ; i < q; i++){
        int x,l,r,t;
        cin>>x;
        if(x==2){
            cin>>l>>r;
            cout<<query(l,r)<<endl;
        }
        else {
            cin>>l>>r>>t;
            fix(l,r,t);
        }
    }
}