#include <map>
#include <bits/stdc++.h>
#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>
#define mod 1000000007
#include <unordered_map>
long long dp[502][502];
using namespace std;
 string s;
long long rec(int i,int j){
if(dp[i][j]!=-1){
    return dp[i][j];
}
 if(i>j){
     dp[i][j]=0;
     return 0;
 }
 if(i==j){
     dp[i][j]=1;
     return 1;
 }
 if(j==i+1){
     dp[i][j]= 2+(s[i]==s[i+1]?1:0);
     return dp[i][j];
 }
    return (((rec(i+1,j)%mod+rec(i,j-1)%mod)%mod-(rec(i+1,j-1))%mod+mod)%mod+(s[i]==s[j]?1:0)*(rec(i+1,j-1)%mod+1)%mod)%mod;
}
/*
g(i, i) = 1 (i.e. when j = i)
g(i, i+1) = 2 + (x[i] == x[i+1]) (i.e. 3 iff adjacent chars are identical, otherwise 2)
g(i, j) = 0 when j < i (this new boundary case is needed)
g(i, j) = g(i+1, j) + g(i, j-1) - g(i+1, j-1) + (x[i] == x[j])*(g(i+1, j-1)+1) when j >= i+2
*/
int main(){
    int n,x,i,j,a,b,c;
    int q;
    cin >> n >> q;
    memset(dp,-1,sizeof(dp));
    cin >> s;
    for(int a0 = 0; a0 < q; a0++){
        cin>>x;
        //cout<<x<<endl;
        if(x==2){
            cin>>i>>j;
            cout<<rec(i,j)<<endl;
        }
        else{
            cin>>a>>b>>c;
        }
    }
    return 0;
}