#include <iostream>
#include <string>
#include <vector>
#include <fstream>
#include <bitset>

using namespace std;

vector<int> V[200001];
char letter[200001];
int t[200001];
int euler[3*200001];
int nivel[3*200001];
int frec[200001][28];
bitset<200001> used;
vector<pair<int, int> >op;
int auxn;
int rmq[3*200001][24];
int log[3*200001];
int f[3*200001];

void create_euler(int nod,int niv)
{
    euler[++auxn] = nod;
    f[nod] = auxn;
    nivel[auxn] = niv;
    frec[nod][letter[nod]-'a']++;
    used[nod] = true;
    for(vector<int>::iterator it = V[nod].begin(); it != V[nod].end(); it++)
    if(!used[*it])
    {
        for(int i = 0; i <= 26; i++)
            frec[*it][i]+=frec[nod][i];
        t[*it] = nod;
        create_euler(*it,niv+1);
        euler[++auxn] = nod;
        nivel[auxn] = niv;

    }
}


int LCA(int x, int y)
{
    x = f[x],y = f[y];
        if(x > y) swap(x,y);
        int l = log[y-x+1];
        if(nivel[rmq[x][l]] < nivel[rmq[y - (1<<l)+1][l]])
            return euler[rmq[x][l]];
        else return euler[rmq[y-(1<<l)+1][l]];
}

void afis(int x, int y)
{
    int sol = 0;
    int L = LCA(x,y);
    int j = 0;
    //cout<<x<<' '<<y<<"   ";
    while(j <= 26)
        {
            if(((frec[x][j] + frec[y][j] - frec[L][j] - frec[t[L]][j]) & 1) == 1)
            {
                sol++;
                //cout<<(char)(j+'a');
            }
            j++;
        }
        cout<<sol<<'\n';
}

int main()
{
    //freopen("1.in","r",stdin);
    //freopen("1.out","w",stdout);
    int n,m;
    used.reset();
    cin>>n>>m;
    for(int i = 1; i <= n; i++)
    {
        cin>>letter[i];
    }
    int a,b,x;
    for(int i = 1; i < n; i++)
    {
        cin>>a>>b;
        V[a].push_back(b);
        V[b].push_back(a);
    }
    char c;
    for(int i = 1; i <= m; i++)
    {
        cin>>x;
        if(x == 1)
        {
            cin>>a>>b;
            op.push_back(make_pair(a,b));
        }
        else
        {
            cin>>a>>c;
            V[a].push_back(++n);
            V[n].push_back(a);
            letter[n] = c;
        }
    }

    create_euler(1,0);
    int nn = n;
    n = auxn;
    for(int i=1;i<=n;i++)
    {
        rmq[i][0] = i;
        if(i>1)
            log[i] = 1+log[i>>1];
    }
    for(int j=1;(1<<j)<=n;j++)
        for(int i=1;i+(1<<j)-1<=n;i++)
            if(nivel[ rmq[i][j-1] ] < nivel[  rmq[i + (1<<(j-1)) ][j-1] ])
                rmq[i][j] = rmq[i][j-1];
            else rmq[i][j] = rmq[i + (1<<(j-1))][j-1];



    for(vector<pair<int, int> >::iterator it = op.begin(); it != op.end(); it++)
    {

        int x = it->first;
        int y = it->second;
        afis(x, y);

    }

/*
    for(int i = 1; i <=n ;i ++)
    {
        for(int j =0;j<=26;j++)
            cout<<frec[i][j]<<' ';
        cout<<'\n';
    }*/
    return 0;
}