#pragma comment(linker, "/STACK:1024000000,1024000000")

#include <cstdio>

#include <string>

#include <cstdlib>

#include <cmath>

#include <iostream>

#include <cstring>

#include <set>

#include <queue>

#include <algorithm>

#include <vector>

#include <map>

#include <cctype>

#include <cmath>

#include <stack>

#define debug puts("+++++")

//#include <tr1/unordered_map>

#define freopenr freopen("in.txt", "r", stdin)

#define freopenw freopen("out.txt", "w", stdout)

using namespace std;

//using namespace std :: tr1;

typedef long long LL;

typedef pair<int, int> P;

const int INF = 0x3f3f3f3f;

const double inf = 0x3f3f3f3f3f3f;

const LL LNF = 0x3f3f3f3f3f3f;

const double PI = acos(-1.0);

const double eps = 1e-8;

const int maxn = 2e5 + 5;

const LL mod = 1e9 + 7;

const int N = 1e6 + 5;

const int dr[] = {-1, 0, 1, 0, 1, 1, -1, -1};

const int dc[] = {0, 1, 0, -1, 1, -1, 1, -1};

const char *Hex[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};

inline LL gcd(LL a, LL b){  return b == 0 ? a : gcd(b, a%b); }

inline int gcd(int a, int b){  return b == 0 ? a : gcd(b, a%b); }

inline int lcm(int a, int b){  return a * b / gcd(a, b); }

int n, m;

const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

inline int Min(int a, int b){ return a < b ? a : b; }

inline int Max(int a, int b){ return a > b ? a : b; }

inline LL Min(LL a, LL b){ return a < b ? a : b; }

inline LL Max(LL a, LL b){ return a > b ? a : b; }

inline bool is_in(int r, int c){

    return r >= 0 && r < n && c >= 0 && c < m;

}

int a[20], b[20];

int c[20], d[20];

int solve(){

    int ans = 0;

    memcpy(a, d, sizeof d);

    for(int i = 0; i < n; ++i){

        if(a[i] == c[i])  continue;

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

            if(a[j] == c[i]){ ans += j-i; a[j] = !c[i];  break; }

    }

    return ans;

}

int main(){

    while(scanf("%d %d", &n, &m) == 2){

        int sum = 0;

        for(int i = 0; i < n; ++i)  scanf("%d", a+i), sum += a[i];

        for(int i = 0; i < m; ++i)  scanf("%d", b+i);

        memcpy(d, a, sizeof a);

        int cnt = 0, s = 0;

        bool ok = true;

        for(int i = 0; i < m; ++i, ok = !ok)

            for(int j = 0; j < b[i]; ++j)

                c[cnt++] = ok, s += ok;

        int ans = INF;

        if(s == sum)  ans = Min(ans, solve());

        s = 0;

        for(int i = 0; i < n; ++i)  c[i] = !c[i],s += c[i];

        if(s == sum) ans = Min(ans, solve());

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

    }

    return 0;

}