#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
int n, q, t, x, y, c;
int dp[511][511];
string s;

int rec( int i, int j ) {
    if( i > j ) return 0;
    int &ret = dp[i][j];
    if( ~ret ) return ret;
    if( i == j ) return ret = 1;
    if( i+1 == j ) return ret = 2 + ( s[i] == s[j] );
    
    ret = rec( i+1, j ) + rec( i, j-1 ) - rec( i+1, j-1 ) + ( s[i] == s[j] ) * ( rec( i+1, j-1 ) + 1 );
    
    return ret %= mod;
}

int main() {
    int cc;
    cin >> n >> q >> s;
    memset( dp, -1, sizeof dp );
    while( q-- ) {
        cin >> t;
        if( t == 1 ) cin >> x >> y >> c;
        else cin >> x >> y;
        if( t == 1 ) {
            c %= 26;
            for( int i=x; i<=y; i++ ) {
                s[i] += c;
                cc = s[i] - 'z';
                if( cc > 0 ) s[i] = 'a' + cc;
            }
            memset( dp, -1, sizeof dp );
        } else {
            cout << rec( x, y ) << "\n";
        }
    }
    return 0;
}