#include <cstdio>

#include <iostream>

#include <algorithm>

#define N 17

#define max(x, y) ((x) > (y) ? (x) : (y))

int n, k, s1, s2, ans = -1;

int a[N], sum[100001], c[N][100001], f[1 << N];

inline int read()

{

	int x = 0, f = 1;

	char ch = getchar();

	for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -1;

	for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - '0';

	return x * f;

}

int main()

{

	int i, j;

	k = read();

	n = read();

	for(i = 1; i <= k; i++) a[i] = read(), s1 += a[i];

	for(i = 1; i <= n; i++) sum[i] = read() + sum[i - 1];

	for(i = 1; i <= k; i++)

		for(j = 1; j <= n; j++)

			c[i][j] = std::upper_bound(sum + j, sum + n + 1, a[i] + sum[j - 1]) - sum - 1;

	for(i = 1; i < (1 << k); i++)

		for(j = 1; j <= k; j++)

			if(i & (1 << j - 1))

				f[i] = max(f[i], c[j][f[i ^ (1 << j - 1)] + 1]);

	for(i = 1; i < (1 << k); i++)

		if(f[i] == n)

		{

			s2 = 0;

			for(j = 1; j <= k; j++)

				if(i & (1 << j - 1))

					s2 += a[j];

			ans = max(ans, s1 - s2);

		}

	printf("%d\n", ans);

	return 0;

}