#include <bits/stdc++.h>
using namespace std;
int main() {
  int h, w;
  cin >> h >> w;
  char a[h][w];
  for (int i = 0; i < h; i++)
    for (int j = 0; j < w; j++) cin >> a[i][j];
  bool ans = 0;
  int t = 0;
  for (int i = 0; i < h; i++)
    for (int j = 0; j < w; j++)
      if (a[i][j] == '*') t++;
  for (int i = 1; i < h - 1; i++) {
    for (int j = 1; j < w - 1; j++) {
      if (a[i][j] != '*') continue;
      int l = 0, r = 0, u = 0, d = 0;
      int k = j - 1;
      while (k >= 0) {
        if (a[i][k] == '*')
          l++;
        else
          break;
        k--;
      }
      k = j + 1;
      while (k < w) {
        if (a[i][k] == '*')
          r++;
        else
          break;
        k++;
      }
      k = i - 1;
      while (k >= 0) {
        if (a[k][j] == '*')
          u++;
        else
          break;
        k--;
      }
      k = i + 1;
      while (k < h) {
        if (a[k][j] == '*')
          d++;
        else
          break;
        k++;
      }
      if (l && r && u && d) {
        if (l + r + d + u + 1 == t) {
          ans = 1;
          break;
        }
      }
    }
    if (ans) break;
  }
  if (ans)
    cout << "YES";
  else
    cout << "NO";
}
