Example

Input

6 3
1 0 0 1 0 1
1 3 2


Output

1
#include "bits/stdc++.h"

#define REP(i,n) for(ll i=0;i<n;++i)
#define RREP(i,n) for(ll i=n-1;i>=0;--i)
#define FOR(i,m,n) for(ll i=m;i<n;++i)
#define RFOR(i,m,n) for(ll i=n-1;i>=m;--i)
#define ALL(v) (v).begin(),(v).end()
#define PB(a) push_back(a)
#define UNIQUE(v) v.erase(unique(ALL(v)),v.end());
#define DUMP(v) REP(aa, (v).size()) { cout << v[a]; if (a != v.size() - 1)cout << " "; else cout << endl; }
#define INF 1000000001ll
#define MOD 1000000007ll
#define EPS 1e-9

const int dx[8] = { 1,1,0,-1,-1,-1,0,1 };
const int dy[8] = { 0,1,1,1,0,-1,-1,-1 };


using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
ll max(ll a, int b) { return max(a, ll(b)); }
ll max(int a, ll b) { return max(ll(a), b); }
ll min(ll a, int b) { return min(a, ll(b)); }
ll min(int a, ll b) { return min(ll(a), b); }
///(?´????????`)(?´????????`)(?´????????`)(?´????????`)(?´????????`)(?´????????`)///
int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	int n, m;
	cin >> n >> m;
	vi v(n), p(m);
	int cnt1 = 0;
	REP(i, n) {
		cin >> v[i];
		cnt1 += v[i];
	}
	REP(i, m)cin >> p[i];
	vi tar(n);
	int cnt = 0;
	REP(i, m) {
		REP(j, p[i]) {
			if (i % 2 == 0) {
				tar[cnt] = 1;
			}
			else {
				tar[cnt] = 0;
			}
			cnt++;
		}
	}
	int cnt2 = 0;
	int ans = INF;
	REP(i, n)cnt2 += tar[i];
	if (cnt1 == cnt2) {
		vi a, b;
		REP(i, n) {
			if (v[i] == 1)a.push_back(i);
			if (tar[i] == 1)b.push_back(i);
		}
		int tmp = 0;
		REP(i, a.size()) {
			tmp += abs(a[i] - b[i]);
		}
		ans = min(ans, tmp);
	}
	REP(i, n)tar[i] = 1 - tar[i];
	cnt2 = n - cnt2;
	if (cnt1 == cnt2) {
		vi a, b;
		REP(i, n) {
			if (v[i] == 1)a.push_back(i);
			if (tar[i] == 1)b.push_back(i);
		}
		int tmp = 0;
		REP(i, a.size()) {
			tmp += abs(a[i] - b[i]);
		}
		ans = min(ans, tmp);
	}

	cout << ans << endl;
	return 0;
}