#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>
#define mod 1000000007
using namespace std;


int main(){
    int on;
    int q;
    cin >> on >> q;
    string s;
    cin >> s;
    int l,r,choice,t;
    for(int a0 = 0; a0 < q; a0++){
        cin>>choice;
        if(choice==1){
            cin>>l>>r>>t;
            for(int i=l;i<=r;i++){
                s[i]=(s[i]-'a'+t)%mod + 'a';
            }
        }
        else{
            cin>>l>>r;
            
            int n = r-l+1;
            string str = s.substr(l,r-l+1);
            
		int store[n+1][n+1];
		for(int i=0;i<=n;i++) {
			for(int j=0;j<=n;j++) {
				if(i==j) {
					store[i][j] = 1;
				} else{
					store[i][j] = 0;
				}
			}
		}
		for(int len=2;len<=n;len++) {
			for(int i=1;i<=n;i++) {
				int j=i+len-1;
				if(j>n) continue;
				if(str[i-1] == str[j-1]) {
					store[i][j] = store[i][j-1]+store[i+1][j]+1;
				} else {
					store[i][j] = store[i][j-1]+store[i+1][j]-store[i+1][j-1];				
				}
			}
		}
		cout << store[1][n]%mod << endl;
            
            
            
        }
    }
    return 0;
}