C++ :

#include<iostream>
#include<cstring>
#define ll long long
#include<set>
#include<map>
using namespace std;
const int N=1e9;
map<int,int>a;

int main(){
	int n,m,s,p,b,c,x;
	cin>>n>>m;
	
	for(int i=0;i<n;i++){
		cin>>x;
		for(int j=0;j<x;j++){
			cin>>s>>p>>b;
	    	a[s]+=p*b;
		}
	}
	ll sum;
	sum=0;
	for(int i=0;i<m;i++){
		cin>>c;
		sum+=a[c];
	}
	cout<<sum<<endl;
	return 0;
}

Python :

# coding=utf-8
n,m=map(int,input().split())
item=[]
for i in range(n):
    n_item=int(input())
    sub_item=[]
    for j in range(n_item):
        sub_item=list(map(int,input().split()))
        item.append(sub_item)

buy_item=[]
for k in range(m):
    buy_item.append(int(input()))
# print(item,buy_item)

money=0
for i in buy_item:
    for j in item:
        # print(j)
        if i==j[0]:
            # print(i,item[0])
            money+=(j[1]*j[2])
print(money)