B

#include<bits/stdc++.h>
using namespace std;

//*****************Data type**********************//
typedef long long ll;
typedef long long int lli;
typedef unsigned long long  ull;
typedef unsigned long long int ulli;

//*****************Map****************************//
typedef map<int, int> mp;
typedef map<int, string> mps;
typedef map<int, char>mpc;
typedef map<string, int>mpsi;
typedef map<char, int>mpci;

//****************Pair****************************//
typedef pair<int, int> pii;
typedef pair<string, string> pss;
typedef pair<char, char> pcc;
typedef pair<int, string> pis;
typedef pair<int, char> pic;

//*****************Vector************************//
typedef vector<int> VI;
typedef vector<string> VS;
typedef vector<double> VD;
typedef vector<lli> VLLI;
typedef vector<VI> VVI;
typedef vector<pii> VPI;

//-------------------------------------------------------------------------------//
#define pp1(A)              printf("%d\n",A)
#define pp2(A,B)            printf("%d %d\n",A,B)
#define pp3(A,B,C)          printf("%d %d %d\n",A,B,C)

#define ss1(A)              scanf("%d", &A)
#define ssl(A)              scanf("%lld", &A)
#define ss2(A,B)            scanf("%d,%d",&A,&B)
#define ss3(A,B,C)          scanf("%d,%d,%d",&A,&B,&C)

//--------------------------------------------------------------------------------//
#define nosync              ios_base::sync_with_stdio(false), cin.tie(NULL)
#define pf                  push_front
#define pb                  push_back
#define popp                pop_back()
#define itr                 iterator
#define mk                  make_pair
#define ff                  first
#define ss                  second
#define END                 return 0
#define line                printf("\n")
#define sq(a)               (a)*(a)
#define SZ(a)               (int)a.size()
#define all(a)              (a).begin(), (a).end()
#define Erase(V,I)          (V).erase((V).begin()+I)
#define Insert(V,I,M)       (V).insert((V).begin()+I,M)

//********************************************************************************//
#define loop(i,n)           for(int i=0;i<n;i++)
#define loop2(i,n)          for(int i=n-1;i>=0;i--)
#define loop3(i,t)          for(int i=1;i<=t;i++)
#define scanV(V, N)         for(int i=0; i<N; i++){ int X; ss1(X); V.pb(X); }
#define scanVll(V, N)       for(int i=0; i<N; i++){ lli X; ssl(X); V.pb(X); }
#define scanA(A, N)         for(int i=0; i<N; i++){ ss1(A[i]); }
#define printA(A, N)        for(int i=0; i<N; i++){ cout<<A[i]<<" "; }
#define printAL(A, N)       for(int i=0; i<N; i++){ cout<<A[i]<<endl; }
#define printV(V, N)        for(int i=0; i<N; i++){ cout<<V[i]<<endl; }
#define vout(v)             for(int i=0;i<v.size();i++){ cout<<v[i]; if(i<v.size()-1) cout<<" "; else cout<<endl;}
#define voutll(V)           for(int i=0; i<V.size(); i++){ cout<<V[i]<<" "; }

/*-----------------------GCD && LCM------------------*/
int gcd(int a, int b) {  return b == 0 ? a : gcd(b , a % b); }
int lcm(int a, int b) {  return a * (b / gcd(a, b)); }
/*---------------------------------------------------*/

//---------------------------------*START*-----------------------------------------//

int main()
{
   int n,m;
   cin>>n>>m;
   string s[n];
   loop(i,n)
   {
       cin>>s[i];
   }
   int count=0;
   loop(i,n)
   {
       loop(j,m)
       {
           if(s[i][j]=='*')
           {
               count++;
           }
       }
   }
   for(int i=1;i<n-1;i++)
   {

       for(int j=1;j<m;j++)
       {
           if(s[i][j]=='.')
           {
               continue;
           }

           if(s[i-1][j]=='*' and s[i+1][j]=='*' and s[i][j-1]=='*' and s[i][j+1]=='*')
           {
               count=count-1;
               for(int k=i-1;k>=0;k--)
               {
                   if(s[k][j]=='*')
                   {
                       count--;
                   }
                   else
                   {
                       break;
                   }
               }
               for(int k=i+1;k<n;k++)
               {
                   if(s[k][j]=='*')
                   {
                       count--;
                   }
                   else
                   {
                       break;
                   }
               }
                for(int k=j-1;k>=0;k--)
               {
                   if(s[i][k]=='*')
                   {
                       count--;
                   }
                   else
                   {
                       break;
                   }
               }
               for(int k=j+1;k<m;k++)
               {
                   if(s[i][k]=='*')
                   {
                       count--;
                   }
                   else
                   {
                       break;
                   }
               }
               if(count==0)
               {
                   cout<<"YES"<<endl;
               }
               else
               {
                   cout<<"NO"<<endl;
               }
               END;
           }
       }
   }
   cout<<"NO"<<endl;
   END;
}