<?php

$ffffff = STDIN;

function depth_picker($arr, $temp_string, &$collect) {
    if ($temp_string != "")
        $collect []= $temp_string;

    for ($i=0; $i<sizeof($arr);$i++) {
        $arrcopy = $arr;
        $elem = array_splice($arrcopy, $i, 1); // removes and returns the i'th element
        if (sizeof($arrcopy) > 0) {
            depth_picker($arrcopy, $temp_string . $elem[0], $collect);
        } else {
            $collect []= $temp_string . $elem[0];
        }
    }
}

function doTwo($string, $from, $to)
{
    if ($from == $to) {
        return 1;
    }

    if ($from - $to == 1) {
        if ($string[$to] == $string[$from]) {
            return 3;
        }
        return 2;
    }

    $substr = substr($string, $from, $to-$from+1);
    $nr = strlen($substr);

    $array = str_split($substr);

    $total = strlen($substr);
    $collect = array();
    depth_picker($array, "", $collect);
    //print_r($collect);
    $c = array_unique($collect);
    //print_r($c);
    foreach ($c as $str) {
        if (strlen($str) == 1) continue;
        if ($str == strrev($str)) {
            $total ++;
            //echo "\ntook $str";
        }
    }

    return $total;
}

$line = array_map('intval', explode(' ', trim(fgets($ffffff))));
$n = $line[0];
$q = $line[1];

$currentString = trim(fgets($ffffff));
for ($ii=1; $ii<=$q; $ii++) {
    $cline = array_map('intval', explode(' ', trim(fgets($ffffff))));
    $op = $cline[0];
    $line = $cline;
    if ($op == 1) {
        $from = $line[1];
        $to = $line[2];
        $do = $line[3];
        $currentString = doOne($currentString, $from, $to, $do);
    }
    if ($op == 2) {
        $from = $line[1];
        $to = $line[2];
        echo doTwo($currentString, $from, $to) . "\n";
    }
}

function doOne($string, $from, $to, $do)
{
    $letters = [];
    for ($i='a'; $i<='z'; $i++) {
        if (strlen($i)==1) {
            $letters[] = $i;
        }
    }

    $inv = array_combine(array_values($letters), array_keys($letters));

    for ($i=$from; $i<=$to; $i++) {
        $val = $inv[$string[$i]] + $do;
        $val = $val % 26;
        $let = $letters[$val];
        $string[$i] = $let;
    }

    return $string;
}