1 #include <cstdio>
 2 #include <cstring>
 3 #define max(x,y) (x >= y ? x : y)
 4 #define MAX 1002
 5 #define LL long long
 6 using namespace std;
 7 
 8 LL a[MAX],sum[MAX],l[22];
 9 LL dp[22][MAX];
10 
11 int main()
12 {
13     int n,m,st;
14     //freopen("data.txt","r",stdin);
15     while(scanf("%d",&n),n){
16         scanf("%d",&m);
17         for(int i=1;i<=m;i++) scanf("%I64d",&l[i]);
18         sum[0]=0;
19         for(int i=1;i<=n;i++){
20             scanf("%I64d",&a[i]);
21             sum[i]=sum[i-1]+a[i];
22         }
23         memset(dp,0,sizeof(dp));
24         st=0;
25         for(int i=1;i<=m;i++){
26             st+=l[i];
27             for(int j=st;j<=n;j++){
28                 dp[i][j]=max(dp[i][j-1],dp[i-1][j-l[i]]+(sum[j]-sum[j-l[i]]));
29             }
30         }
31         printf("%I64d\n",dp[m][n]);
32     }
33     return 0;
34 }