Count the number of components with Xor as given

ll cnt =0;
ll dfs(ll i,ll pre,vector<ll>&a,vector<vector<ll>>&edges,ll val){
    ll cur = a[i];
    for(auto x:edges[i]){
        if(x==pre)
        continue;
        cur^=dfs(x,i,a,edges,val);
    }
    if(cur==val)
    ++cnt,cur = 0;
    return cur;
}