#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define all(x) (x).begin(), (x).end()
bool be;
constexpr int N = 55;
char s[N][N];
int x[8], y[8];
int calc(int xx, int yy)
{
	x[0] = xx - 1, y[0] = yy - 1;
	x[1] = xx - 1, y[1] = yy;
	x[2] = xx - 1, y[2] = yy + 1;
	x[3] = xx, y[3] = yy - 1;
	x[4] = xx, y[4] = yy + 1;
	x[5] = xx + 1, y[5] = yy - 1;
	x[6] = xx + 1, y[6] = yy;
	x[7] = xx + 1, y[7] = yy + 1;
	int ans = 0;
//	cerr << x[2] << ' ' << y[2] << '\n';
//	cerr << s[x[2]][y[2]];
//	cerr << (s[x[0]][y[0]] == '\\' && s[x[1]][y[1]] == '|' && s[x[2]][y[2]] == '/');
	while (s[x[0]][y[0]] == '\\' && s[x[1]][y[1]] == '|' && s[x[2]][y[2]] == '/' && s[x[3]][y[3]] == '-' && s[x[4]][y[4]] == '-' && s[x[5]][y[5]] == '/' && s[x[6]][y[6]] == '|' && s[x[7]][y[7]] == '\\') {
		--x[0], --y[0];
		--x[1];
		--x[2], ++y[2];
		--y[3];
		++y[4];
		++x[5], --y[5];
		++x[6];
		++x[7], ++y[7];
		++ans;
	}
	return ans;
}
bool en;
int main()
{
	cerr << (&be - &en) / 1024.0 / 1024 << " MB\n--------------------------------" << endl;
#ifdef IAKIOI
	freopen("in.in", "r", stdin);
//	freopen("out.out", "w", stdout);
#endif
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, m;
	cin >> n >> m;
	for (int i = 1; i <= n; ++i) {
		for (int j = 1; j <= m; ++j) {
			cin >> s[i][j];
		}
	}
	int ans = 0;
	for (int i = 1; i <= n; ++i) {
		for (int j = 1; j <= m; ++j) {
			if (s[i][j] == '+') {
				ans = max(ans, calc(i, j));
			}
		}
	}
	cout << ans << endl;
	return 0;
}