进食后人（如果你也60pts

#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int N=1e5+5;
ll n, m, a, b, c, cit[N], p1, p2, ans;
int main(){
 scanf("%lld %lld", &n, &m);//rt
 if(m)
 	scanf("%lld", &p1);//rt
 for(int i=2; i<=m; i++){
 	scanf("%lld", &p2);//rt
 	cit[min(p1, p2)]++; cit[max(p1, p2)]--;//前缀和，从p1到p2 
 	p1=p2;
 }
 for(int i=1; i<n; i++){
 	cit[i]+=cit[i-1];
 	scanf("%lld %lld %lld", &a, &b, &c);//rt
 	if(cit[i])//如果经过 
 		ans+=min(a*cit[i], b*cit[i]+c);
 }
 if(!m || !(m-1))
 	putchar('0');
 printf("%lld\n", ans);//rt
 return 0;
}