#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 100;
const long long inf = 1e18;
long long w, h;
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};
string str[1000];
int main() {
  cin >> h >> w;
  for (int i = 0; i < h; i++) {
    cin >> str[i];
  }
  long long cnt = 0;
  for (int i = 0; i < h; i++) {
    for (int j = 0; j < w; j++) {
      if (str[i][j] == '*') cnt++;
    }
  }
  for (int i = 0; i < h; i++) {
    for (int j = 0; j < w; j++) {
      if (str[i][j] == '*') {
        long long up, dw, lf, rh;
        up = dw = lf = rh = 0;
        for (int p = j + 1; p < w; p++) {
          if (str[i][p] == '*')
            rh++;
          else
            break;
        }
        for (int p = j - 1; p >= 0; p--) {
          if (str[i][p] == '*')
            lf++;
          else
            break;
        }
        for (int p = i + 1; p < h; p++) {
          if (str[p][j] == '*')
            dw++;
          else
            break;
        }
        for (int p = i - 1; p >= 0; p--) {
          if (str[p][j] == '*')
            up++;
          else
            break;
        }
        if ((1 + up + dw + lf + rh) == cnt and up && dw && lf && rh) {
          cout << "YES\n";
          return 0;
        }
      }
    }
  }
  cout << "NO\n";
  return 0;
}
