#include <bits/stdc++.h>
using namespace std;
void showvec(vector<long long> v) {
  for (long long i = 0; i < v.size(); i++) {
    cout << v[i] << " ";
    ;
  }
  cout << "\n";
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long t, i, j, k;
  long long n, m, total = 0;
  cin >> n >> m;
  char arr[n][m];
  for (long long i = 0; i < n; ++i) {
    for (long long j = 0; j < m; ++j) {
      cin >> arr[i][j];
      if (arr[i][j] == '*') total++;
    }
  }
  long long row[n], col[m], count = 0;
  for (i = 0; i < n; ++i) {
    count = 0;
    for (j = 0; j < m; ++j) {
      if (arr[i][j] == '*') count++;
    }
    row[i] = count;
  }
  for (j = 0; j < m; ++j) {
    count = 0;
    for (i = 0; i < n; ++i) {
      if (arr[i][j] == '*') count++;
    }
    col[j] = count;
  }
  bool flag = 0;
  for (long long i = 0; i < n; ++i) {
    for (long long j = 0; j < m; ++j) {
      if (arr[i][j] == '*' and i > 0 and j > 0 and i < n - 1 and j < m - 1) {
        if (arr[i][j - 1] == '*' and arr[i][j + 1] == '*' and
            arr[i - 1][j] == '*' and arr[i + 1][j] == '*') {
          long long it = i;
          count = 1;
          while (it > 0) {
            if (arr[it - 1][j] == '*')
              count++;
            else
              break;
            it--;
          }
          it = i;
          while (it < n) {
            if (arr[it + 1][j] == '*')
              count++;
            else
              break;
            it++;
          }
          it = j;
          while (it > 0) {
            if (arr[i][it - 1] == '*')
              count++;
            else
              break;
            it--;
          }
          it = j;
          while (it < m) {
            if (arr[i][it + 1] == '*')
              count++;
            else
              break;
            it++;
          }
          if (count == total) {
            flag = 1;
            break;
          }
        }
      }
      if (flag) break;
    }
  }
  if (flag)
    cout << "YES"
         << "\n";
  else
    cout << "NO"
         << "\n";
}
