/*
    Look at me!
    Look at me!
    Look at how large the monster inside me has become!
*/

#include<fstream>
#include<iostream>
#include<cstdio>
#include<map>
#include<set>
#define FIT(a,b) for(vector<int >::iterator a=b.begin();a!=b.end();a++)
#define FITP(a,b) for(vector<pair<int,int> >::iterator a=b.begin();a!=b.end();a++)
#define RIT(a,b) for(vector<int>::reverse_iterator a=b.end();a!=b.begin();++a)
#include<stack>
#define ROF(a,b,c) for(int a=b;a>=c;--a)
#include<vector>
#include<algorithm>
#define FOR(a,b,c) for(int a=b;a<=c;++a)
#define REP(a,b) for(register int a=0;a<b;++a)
#include<cstring>
#include<ctime>
#include<bitset>
#include<cmath>
#include<iomanip>
#include<set>
#define f cin
#define g cout
#include<queue>
#define debug cerr<<"OK";
#define pii pair<int,int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define ll long long
#define ull unsigned long long
#define mod 1000000009LL
#define SQR 350
#define inf 1<<30
#define div fdasfasd
#define hash dsafdsfds
#define od 666013
#define mod 1000000007
#define DIM 600100
#define N 2001
using namespace std;
/*
    int dx[]={0,0,0,1,-1};
    int dy[]={0,1,-1,0,0};
*/

vector<int> v[N];
vector<int> P[N];
char s[N],ch;
int S[30][N],tip[N],a[N],b[N],m,nrl,x,y,poz[N],lant[N],subarb[N],niv[N],T[N],n;
void dfs(int x,int lvl,int p)
{
    niv[x]=lvl;
    T[x]=p;
    subarb[x]=1;

    FOR(lit,1,26)
    S[lit][x]=S[lit][p];
    S[s[x]-'a'+1][x]++;
    FIT(it,v[x])
    if(*it!=p)
    {
        dfs(*it,lvl+1,x);
        subarb[x]+=subarb[*it];

    }



    if(subarb[x]==1)
    {
        ++nrl;
       lant[x]=nrl;
       P[nrl].pb(0);
       P[nrl].pb(x);
       return ;
    }

    int be=0;
    FIT(it,v[x])
    if(*it!=p)
    {
        if(subarb[*it]>subarb[be])
            be=*it;
    }
    lant[x]=lant[be];
    P[lant[x]].pb(x);
}
int sum(int x,int lit)
{
    return S[lit][x];
}
int lca(int x,int y)
{
    while(1)
    {
        if(lant[x]==lant[y])
        {
            if(niv[x]<niv[y])
                return x;
            return y;
        }
        int a=P[lant[x]][1];
        int b=P[lant[y]][1];
        if(niv[a]<niv[b])
            swap(x,y);
        x=T[P[lant[x]][1]];
    }
}
int main ()
{
    #ifndef ONLINE_JUDGE
    freopen("a.in","r",stdin);
    freopen("a.out","w",stdout);
    #endif
    
    f>>n>>m;
    f>>(s+1);
    FOR(i,1,n-1)
    {
        f>>x>>y;
        v[x].pb(y);
        v[y].pb(x);
    }
    FOR(i,1,m)
    {
        f>>tip[i]>>a[i];
        if(tip[i]==2)
        {
            f>>ch;
            v[a[i]].pb(++n);
            v[n].pb(a[i]);
            s[n]=ch;
        }
        else
        {
            f>>b[i];
        }
    }
    FOR(i,1,nrl)
    {
        int siz=P[i].size();
        siz--;
        FOR(j,1,siz/2)
            swap(P[i][j],P[i][siz-j+1]);
    }
    dfs(1,1,0);
    FOR(i,1,m)
    {
        if(tip[i]==1)
        {
            int sol=0;
            int x=lca(a[i],b[i]);
            FOR(let,1,26)
            {
                if((sum(a[i],let)+sum(b[i],let)-sum(x,let)-sum(T[x],let))%2)
                    sol++;
            }
            g<<sol<<"\n";
        }
    }
    return 0;
}