#include<cstdio>
#include<fstream>
#include<iostream>
#include<iomanip>
#include<algorithm>
#include<vector>
#include<bitset>
#include<deque>
#include<queue>
#include<set>
#include<map>
#include<cmath>
#include<cstring>
#include<ctime>
#include<cstdlib>
#include<unordered_map>

#define ll long long
#define pb push_back
#define mp make_pair
#define pii pair<int,int>
#define pll pair<ll,ll>
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second

using namespace std;

const int nmax = 200005;
const int lmax = 19;

int n, m, i, j, x, y, op, dif, lca, mlc, X, Y, lev[nmax], sum[nmax], val[nmax], f[lmax][nmax];
char c;

vector<int> v[nmax];

void dfs(int x, int d)
{
    sum[x] = val[x] ^ sum[d];
    for(auto it : v[x])
        if(it != d)
        {
            f[0][it] = x;
            lev[it] = lev[x] + 1;
            dfs(it, x);
        }
}

int count(int x)
{
    int cnt = 0;

    for(int i = 0; i < 30; i++)
        if((1 << i) & x)
            cnt++;

    return cnt;
}

int main()
{
    cin.sync_with_stdio(false);

    //    freopen("test.in", "r", stdin);
//    freopen("test.out", "w", stdout);

    cin >> n >> m;

    for(i = 1; i <= n; i++)
    {
        cin >> c;
        val[i] = 1 << (c - 'a');
    }

    for(i = 1; i < n; i++)
    {
        cin >> x >> y;
        v[x].pb(y);
        v[y].pb(x);
    }

    lev[1] = 1;
    dfs(1, 0);

    for(i = 1; (1 << i) <= n; i++)
        for(j = 1; j <= n; j++)
            f[i][j] = f[i - 1][f[i - 1][j]];

    for(; m; m--)
    {
        cin >> op;

        if(op == 2)
        {
            cin >> x >> c;
            ++n;
            f[0][n] = x;
            val[n] = 1 << (c - 'a');
            sum[n] = sum[x] ^ val[n];
            lev[n] = lev[x] + 1;

            for(i = 1; (1 << i) <= n; i++)
                f[i][n] = f[i - 1][f[i - 1][n]];
        }
        else
        {
            cin >> x >> y;

            if(lev[x] > lev[y]) swap(x, y);
            X = x;
            Y = y;
            dif = lev[y] - lev[x];

            for(i = 0; i < 18; i++)
                if((1 << i) & dif) y = f[i][y];

            if(x == y) lca = x;
            else
            {
                for(i = 17; i >= 0; i--)
                    if(f[i][x] != f[i][y])
                    {
                        x = f[i][x];
                        y = f[i][y];
                    }
                lca = f[0][x];
            }

            if(lca == x) mlc = sum[Y] ^ sum[f[0][X]];
            else mlc = sum[X] ^ sum[f[0][lca]] ^ sum[Y] ^ sum[f[0][lca]] ^ val[lca];

            cout << count(mlc) << '\n';
        }
    }

    return 0;
}