#include <cstdio>

 #include <cstring>

 #include <cstdlib>

 #include <algorithm>

 #include <iostream>

 using namespace std;

 #define MAXN 1020

 #define MAXM 35

 #define INF 0xfffff

 int dp[MAXM][MAXN];

 int l[MAXM];

 int sums[MAXN];

 int main() {

     int n, m, sum;

     int i, j, k, tmp;

 #ifndef ONLINE_JUDGE

     freopen("data.in", "r", stdin);

     freopen("data.out", "w", stdout);

 #endif

     while (scanf("%d",&n)!=EOF && n) {

         scanf("%d", &m);

         for (i=; i<=m; ++i)

             scanf("%d", &l[i]);

         sums[] = ;

         for (i=; i<=n; ++i) {

             scanf("%d", &tmp);

             sums[i] = sums[i-] + tmp;

         }

         sum = ;

         memset(dp, , sizeof(dp));

         for (i=m; i>; --i) {

             sum += l[i];

             for (j=n-sum+; j>; --j) {

                 dp[i][j] = max( dp[i][j+], dp[i+][j+l[i]]+(sums[j+l[i]-]-sums[j-]) );

             }

         }

         printf("%d\n", dp[][]);

     }

     return ;

 }