cf1118f1

#include"stdio.h"
#include"string.h"
#include"algorithm"
using namespace std;

const int N = 20010,M = 1001010;
int head[N],ver[M],Next[M],tot;
int a[N],n;
int num1[N],num2[N];

void add(int x,int y)
{
    ver[++ tot] = y; Next[tot] = head[x]; head[x] = tot;
}

void dfs(int x,int far)
{
    if(a[x] == 1) num1[x] = 1;
    else if(a[x] == 2)num2[x] = 1;
    for(int i = head[x]; i; i = Next[i]){
        int y = ver[i];
        if(y == far) continue;
        dfs(y,x);
        num1[x] += num1[y];
        num2[x] += num2[y];
    }
}
int main()
{
    scanf("%d",&n);
    for(int i = 1; i <= n; i ++) scanf("%d",&a[i]);
    for(int i = 1; i