Example

Input

6 3
1 0 0 1 0 1
1 3 2


Output

1
#include <bits/stdc++.h>

using namespace std;

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}
template<class T> inline T sqr(T x) {return x*x;}

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;

#define all(a)  (a).begin(),(a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define pb push_back
#define mp make_pair
#define each(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define exist(s,e) ((s).find(e)!=(s).end())
#define range(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n)  range(i,0,n)
#define clr(a,b) memset((a), (b) ,sizeof(a))
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

const double eps = 1e-10;
const double pi  = acos(-1.0);
const ll INF =1LL << 62;
const int inf =1 << 29;

string bit;
string pattern[2];

int sw(string b,string p){
	int n=b.size();
	int res=0;
	for(int i=0;i<n;++i){
		if(b[i]==p[i])
			continue;
		for(int j=i+1;j<n;++j){
			if(b[j]==p[i]){
				res+=(j-i);
				swap(b[i],b[j]);
				break;
			}
		}
	}
	if(b==p)
		return res;
	return inf;
}

int run[15];

int main(void){
	int n,m;
	cin >> n >> m;
	rep(i,n){
		int in;
		cin >> in;
		bit+=(in+'0');
	}
	rep(i,m) cin >> run[i];

	rep(i,2){
		int cur=i;
		rep(j,m){
			rep(k,run[j]) pattern[i]+=('0'+cur);
			cur^=1;
		}
	}
	cout << min(sw(bit,pattern[0]),sw(bit,pattern[1])) << endl;
	return 0;
}