#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <deque>
#include <set>
#include <map>
#include <algorithm>

#include <cmath>
#include <ctime>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
using namespace std;

const int INF = 0x3f3f3f3f;
const double EPS = 1e-11;
const double PI = 3.141592653589793;
const int MAX_N = 300005;
const long long LLINF = 99999999999999999LL;
const int SIGMA = 26;

int N, M;
int D[MAX_N][20], S[MAX_N][20][SIGMA], lv[MAX_N], F[MAX_N], a[SIGMA];
vector < int > v[MAX_N], Level[MAX_N];
char val[MAX_N];
bool vis[MAX_N];

void DFS(int x) {
    vis[x] = 1;
    Level[lv[x]].push_back(x);
    for(int i = 0; i < (int) v[x].size(); ++i) {
        int y = v[x][i];

        if(vis[y])
            continue;

        lv[y] = lv[x] + 1;
        F[y] = x;
        DFS(y);
    }
}

int main() {
/*
    #ifndef ONLINE_JUDGE
        freopen("data.in", "r", stdin);
    #endif
*/
    cin >> N >> M;
    for(int i = 1; i <= N; ++i)
        cin >> val[i];

    for(int i = 1; i < N; ++i) {
        int x, y;

        scanf("%d %d", &x, &y);

        v[x].push_back(y);
        v[y].push_back(x);
    }

    lv[1] = 1;
    DFS(1);

    for(int i = 1; i <= N; ++i) {
        for(int j = 0; j < (int) Level[i].size(); ++i) {
            int x = Level[i][j];

            D[x][0] = F[x];
            S[x][0][val[F[x]] - 'a']++;
            for(int k = 1; (1 << k) <= i; ++k) {
                D[x][k] = D[D[x][k - 1]][k - 1];
                for(int h = 0; h < SIGMA; ++h)
                    S[x][k][h] = S[x][k - 1][h] + S[D[x][k - 1]][k - 1][h];
            }
        }
    }

    for(int q = 1; q <= M; ++q) {
        int t, x, y;
        char c;

        scanf("%d", &t);
        if(t == 1) {
            scanf("%d %d", &x, &y);

            for(int i = 0; i < SIGMA; ++i)
                a[i] = 0;

            if(lv[x] < lv[y])
                swap(x, y);

            int i = 0, j = 0;
            for(int k = 1; k <= 19; ++k) {
                if((1 << k) <= lv[x])
                    i = k;
                if((1 << k) <= lv[y])
                    j = k;
            }

            int lca = 0, x1 = x, y1 = y;
            for(int k = i; k >= 0; --k)
                if(lv[x] - (1 << k) >= lv[y])
                    x = D[x][k];

            if(x == y)
                lca = x;
            else {
                for(int k = j; k >= 0; --k)
                    if(D[x][k] && D[x][k] != D[y][k]) {
                        x = D[x][k];
                        y = D[y][k];
                    }
                lca = D[x][0];
            }


            //
            x = x1; y = y1;

            while(x != lca) {
                i = 0;
                for(int k = 1; k <= 19; ++k)
                    if(lv[D[x][k]] >= lv[lca])
                        i = k;

                for(int h = 0; h < SIGMA; ++h)
                    a[h] += S[x][i][h];
                x = D[x][i];
            }

            while(y != lca) {
                i = 0;
                for(int k = 1; k <= 19; ++k)
                    if(lv[D[y][k]] >= lv[lca])
                        i = k;

                for(int h = 0; h < SIGMA; ++h)
                    a[h] += S[y][i][h];
                y = D[y][i];
            }

            ++a[val[x1] - 'a'];
            ++a[val[y1] - 'a'];
            --a[val[lca] - 'a'];

            int ans = 0;
            for(int i = 0; i < SIGMA; ++i)
                if(a[i] % 2)
                    ++ans;

            printf("%d\n", ans);
        }
        else {
            scanf("%d %c", &x, &c);

            ++N;
            y = N;

            lv[y] = lv[x] + 1;
            F[y] = x;
            val[y] = c;

            swap(x, y);

            D[x][0] = F[x];
            S[x][0][val[F[x]] - 'a']++;
            for(int k = 1; (1 << k) <= lv[x]; ++k) {
                D[x][k] = D[D[x][k - 1]][k - 1];
                for(int h = 0; h < SIGMA; ++h)
                    S[x][k][h] = S[x][k - 1][h] + S[D[x][k - 1]][k - 1][h];
            }
        }
    }

    return 0;
}