#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <queue>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

static const double EPS = 1e-8;
static const double PI = 4.0 * atan(1.0);
static const double PI2 = 8.0 * atan(1.0);

#define REP(i,n)	for(int i=0;i<(int)n;++i)
#define ALL(c)		(c).begin(),(c).end()
#define CLEAR(v)	memset(v,0,sizeof(v))
#define MP(a,b)		make_pair((a),(b))
#define ABS(a)		((a)>0?(a):-(a))
#define FOR(i,s,n)	for(int i=s;i<(int)n;++i)

char days[50];

int main(int argc, char **argv) {
	int D;
	cin >> D;
	REP(i, 14 * 3) days[i] = 'x';
	REP(i, 14) cin >> days[14 + i];
	int res = D;
	REP(i, 14 * 3) {
		int cnt = 0;
		REP(j, D) if (days[i + j] == 'o') cnt = -1;
		if (cnt == -1) continue;
		REP(j, 14 * 3) {
			if (days[j] == 'o' || (j >= i && j < i + D)) {
				++cnt;
			}
			else {
				res = max(res, cnt);
				cnt = 0;
			}
		}
	}
	cout << res << endl;
	return 0;
}