#include <bits/stdc++.h>

#define F first
#define S second
#define mp make_pair
#define pb push_back
#define sz(x) x.size()
#define all(x) x.begin(), x.end()
#define pii pair < int , int >

using namespace std;

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;

const int N = 1e6 + 123;
const int mod = 1e9 + 7;
const int INF = 1e9 + 1;
const ll INFL = 3e18 + 1;
const double pi = acos(-1.0);

int n, q;
string s;
ll dp[5000][5000];

ll calc (int l, int r){
	if (l > r)return 0ll;
	if (l == r)return 1ll;
	if (dp[l + 1][r] == 0)dp[l + 1][r] = calc (l + 1, r) % mod;
	if (dp[l][r - 1] == 0)dp[l][r - 1] = calc (l, r - 1) % mod;
	if (dp[l + 1][r - 1] == 0)dp[l + 1][r - 1] = calc (l + 1, r - 1) % mod;
	dp[l][r] = (((dp[l + 1][r] + dp[l][r - 1]) % mod - dp[l + 1][r - 1]) + mod) % mod;
	if (s[l] == s[r])dp[l][r] += (dp[l + 1][r - 1] + 1) % mod;
	return dp[l][r] % mod;
}
int main () {
	
	ios_base::sync_with_stdio (0);
	cin.tie (0);
	cin >> n >> q >> s;
	while (q --) {
		int tp, l, r, t;
		cin >> tp;
		if (tp == 1) {
			cin >> l >> r >> t;
			for (int i = l;i <= r;i ++) s[i] = (s[i] + t - 26);
			memset (dp, 0, sizeof dp);
		}
		else {
			cin >> l >> r;
			cout << calc (l, r) % mod << endl;
		}
	}


return 0;       
}