#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAXN = 2e5+10,mod = 998244353;
int addv(int x,int y){return (x+y>=mod)?(x+y-mod):(x+y);}
int subv(int x,int y){return (x>=y)?(x-y):(x-y+mod);}
void add(int& x,int y){x = addv(x,y);}
void sub(int& x,int y){x = subv(x,y);}
int qpow(int a,int n){
    int res = 1; a%=mod;
    while(n){
        if(n&1)res = 1ll*res*a%mod;
        n>>=1; a = 1ll*a*a%mod;
    }
    return res;
}
int qinv(int a){return qpow(a,mod-2);}
//
int n; string s;
vector<int> e[MAXN];

int f[MAXN][3],sz[MAXN],sx[MAXN];
typedef array<int,2> pr;
map<pr,int> q;

void merge(int u,int v){
    int g[3] = {};
    for(int x=-1;x<=1;x++)for(int y=-1;y<=1;y++)if(abs(x+y) <= 1){
        add(g[x+y+1],1ll*f[u][x+1]*f[v][y+1]%mod);
    }
    f[u][0] = g[0],f[u][1] = g[1],f[u][2] = g[2];
}

void dfs(int u,int fa){
    sz[u] = 1; 
    if(s[u] == 'S'){
        sx[u] = 1;
        f[u][0] = f[u][1] = 1;
    }else{
        sx[u] = 0;
        f[u][1] = f[u][2] = 1;
    }

    for(auto v : e[u])if(v != fa){
        dfs(v,u);
        merge(u,v);
        sz[u] += sz[v]; sx[u] += sx[v];
    }
    if(q.find((pr){u,fa}) == q.end()){
        f[u][0] = 0;
    }
    if(q.find((pr){fa,u}) == q.end()){
        f[u][2] = 0;
    }
    for(int x=-1;x<=1;x++)if(sx[u]+x < 0 || sx[u]+x > sz[u]){
        f[u][x+1] = 0;
    }
}

int main(){
    ios::sync_with_stdio(false); cin.tie(0);

    cin>>n>>s; s = " "+s;
    for(int i=1,u,v;i<n;i++){
        cin>>u>>v;
        e[u].push_back(v); e[v].push_back(u);
        q[(pr){u,v}] = 1;
    }
    dfs(1,0);
    cout<<f[1][1]<<endl;
    return 0;
}