求调

#include <bits/stdc++.h>

using namespace std;

const int maxn = 1550;
int n,dp[maxn][2];
vector<int> v[maxn];

void dfs(int u,int fa)
{
    dp[u][1] = 1;
    for (int i = 0;i < (int)v[u].size();i++) if (v[u][i] != fa)
    {
        int to = v[u][i];
        dfs(to,u);
        dp[u][0] += dp[to][1];
        dp[u][1] += min(dp[to][0],dp[to][1]);
    }
}

int main()
{
    scanf ("%d",&n);

    for (int i = 1;i <= n;i++)
    {
        int id,k;
        scanf ("%d%d",&id,&k);
        for (int j = 1;j <= k;j++)
        {
            int u;
            scanf ("%d",&u);
            v[id].push_back(u);
            v[u].push_back(id);
        }
    }

    dfs(1,0);
    printf ("%d",min(dp[1][0],dp[1][1]));

    return 0;
}