Example

Input

6 3
1 0 0 1 0 1
1 3 2


Output

1
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <functional>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <utility>
#include <sstream>
#include <complex>
#include <fstream>
#include <bitset>
#include <time.h>
#include <tuple>
#include <iomanip>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> P;
typedef vector<ll> V;
typedef complex<double> Point;

#define PI acos(-1.0)
#define EPS 1e-10
const ll INF = 1e12;
const ll MOD = 1e9 + 7;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define rep(i,N) for(int i=0;i<(N);i++)
#define ALL(s) (s).begin(),(s).end()
#define EQ(a,b) (abs((a)-(b))<EPS)
#define EQV(a,b) ( EQ((a).real(), (b).real()) && EQ((a).imag(), (b).imag()) )
#define fi first
#define se second
#define N_SIZE (1LL << 20)
#define NIL -1

ll sq(ll num) { return num*num; }
ll mod_pow(ll x, ll n) {
	if (n == 0)return 1;
	if (n == 1)return x%MOD;
	ll res = sq(mod_pow(x, n / 2));
	res %= MOD;
	if (n % 2 == 1) {
		res *= x;
		res %= MOD;
	}
	return res;
}
ll mod_add(ll a, ll b) { return (a + b) % MOD; }
ll mod_sub(ll a, ll b) { return (a - b + MOD) % MOD; }
ll mod_mul(ll a, ll b) { return a*b % MOD; }

ll n, m;
bool bb[100];
ll p[100];

int main() {
	cin >> n >> m;
	rep(i, n)cin >> bb[i];
	rep(i, m)cin >> p[i];
	ll ans = INF;
	rep(i, 2) {
		bool b[100];
		bool ok = true;
		ll sum = 0;
		int now = 0;
		int cnt = 0;
		bool f = i;
		rep(j, 100)b[j] = bb[j];
		rep(j, n) {
			if (f != b[j]) {
				//cout << j;
				ll pos = -1;
				FOR(k, j + 1, n) {
					if (f == b[k]) {
						pos = k;
						break;
					}
				}
				if (pos == -1)ok = false;
				else {
					for (int k = pos; k > j; k--) {
						swap(b[k], b[k - 1]);
						sum++;
					}
				}
			}
			cnt++;
			if (cnt == p[now]) {
				now++;
				cnt = 0;
				f = !f;
			}
		}
		//cout << endl;
		//cout << sum << endl;
		if (ok)ans = min(ans, sum);
	}
	cout << ans << endl;
}
