#include <bits/stdc++.h>
using namespace std;
int main() {
  int h, w;
  cin >> h >> w;
  char v[h][w];
  int cnt = 0;
  for (int i = 0; i < h; i++)
    for (int j = 0; j < w; j++) cin >> v[i][j];
  for (int i = 0; i < h; i++)
    for (int j = 0; j < w; j++)
      if (v[i][j] == '*') cnt++;
  for (int i = 1; i < h - 1; i++) {
    for (int j = 1; j < w - 1; j++) {
      if (v[i][j] != '*')
        continue;
      else if (v[i - 1][j] == '*' && v[i][j - 1] == '*' && v[i + 1][j] == '*' &&
               v[i][j + 1] == '*') {
        for (int k = i - 1; k >= 0; k--) {
          if (v[k][j] == '*')
            cnt--;
          else
            break;
        }
        for (int k = j - 1; k >= 0; k--) {
          if (v[i][k] == '*')
            cnt--;
          else
            break;
        }
        for (int k = i + 1; k < h; k++) {
          if (v[k][j] == '*')
            cnt--;
          else
            break;
        }
        for (int k = j + 1; k < w; k++) {
          if (v[i][k] == '*')
            cnt--;
          else
            break;
        }
        if (cnt == 1) {
          cout << "YES" << endl;
          return 0;
        }
        cout << "NO" << endl;
        return 0;
      }
    }
  }
  cout << "NO" << endl;
}
