#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
pair<int,int> find_center(vector <string> S, int m)
{
    pair<int, int> temp;
    temp.first = 0;
    temp.second = 0;
    for (int i = 1; i < S.size()-1; i++)
    {
        for (int j = 1; j < m - 1; j++)
        {
            if (S[i - 1][j] == '*' && S[i + 1][j] == '*' && S[i][j + 1]=='*' && S[i][j - 1] == '*')
            {
                temp.first = i;
                temp.second = j;
                return temp;
            }
        }
    }
    return temp;
}
int main()
{
    int h, w;
    cin >> h>> w;
    vector <string> s;
    s.resize(h);

    int count_pluses = 0;
    for (int i = 0; i < h; i++)
    {
        cin >> s[i];
        for (int j = 0; j < w; j++)
        {
            if (s[i][j] == '*')
            {
                count_pluses++;
            }
        }
    }
     pair<int, int> coord = find_center(s, w);
    int count_temp = 0;
    if (coord.first == 0 && coord.second == 0)
    {
        cout << "NO";
        return 0;
    }
    int l, d;
    for (int k = 1; k <= 4; k++)
    {

        l = coord.first;
        d = coord.second;
        while (l < s.size() && l>=0 && d < w&&d>=0&& s[l][d] == '*')
        {
            count_temp++;
            switch (k)
            {
            case 1:
            {

                l++;
                break;
            }
            case 2:
            {
                l--;
                break;
            }
            case 3:
            {
                d++;
                break;
            }
            case 4:
                d--;
                break;
            default:
                break;
            }
        }

    }
    if (count_temp -3 == count_pluses)
        cout << "YES" << endl;
    else cout << "NO" << endl;

}