又是一天

某道古代修鸟巢的题
代码：

#include<bits/stdc++.h>
using namespace std;
#define go(i,a,b) for(register int i=(a);i<=(b);++(i))
#define come(i,a,b) for(register int i=(a);i>=(b);--(i))
#define mem(a,b) memset((a),(b),sizeof(a))
#define inf 0x3f3f3f3f
vector<int>g[10005];int a[10005],vis[10005];
typedef long long ll

void read(int &x){
    int f=1;
    char s=getchar();
    x=0;
    while(!isdigit(s)){
        if(s=='-')f=-1;
        s=getchar();
        }
    while(isdigit(s)){
        x=(x<<3)+(x<<1)+s-'0';
        s=getchar();
        }
    x*=f;
    }
    
int dp(int u){
    int ans=a[u];
    vis[u]=1;
    int n=g[u].size();
    int v;
    for(int i=0;i<n;i++){        
        v=g[u][i];        
        if(vis[v])continue;
        ans+=dp(v);
    }    
    return ans;
}  

int main(){    
#ifdef DEBUG
    freopen("input.txt","r",stdin);    
#endif
    int n,m;    
    read(n),read(m);    
    go(i,1,n){     
        int v;       
        scanf("%d",&a[i]);        
        while(getchar()==' '){            
            scanf("%d",&v);            
            g[i].push_back(v);        
            }    
        }    
    printf("%d",dp(m));    
    return 0;
}