#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <unordered_map>

using namespace std;

int countPalindrome(char *str)
{
	int i,j,k,count=0;
	for(i=0;str[i];i++)
	{
		k=i-1;j=i+1;  //count odd length palindromes
		while(k>=0 && str[j] && str[k]==str[j])
		{
			++count;
			k--;j++;
		}

		k=i;j=i+1; //count even length palindrome
		while(k>=0 && str[j] && str[k]==str[j])
		{
			++count;
			k--;j++;
		}
	}
	return count;
}
int main(){
    int n;
    int q;
    cin >> n >> q;
    string s;
    cin >> s;
    for(int a0 = 0; a0 < q; a0++){
        int t, i, j, p;
        cin >> t >> i >> j;
        if(t==1){
            cin >> p;
            for(int k=i; k<=j; k++){
                s[k] = (int)s[k]+p;
            }
        }
        else{
            char s1[j-i];
            int c=0;
            for(int k=i; k<=j; k++){
                s1[c++] = s[k];
                
            }
            cout << countPalindrome(s1) << endl;
        }
    }
    return 0;
}