#include<iostream>
using namespace std;
int main()
{
int a, b;
cin >> a;
cin >> b;
if (b == 0 )
return 0; //if b is not input
if (b % 2 != 0)
{
for (int i(0); i < a*b; i++)
{
if (i > 0 && i%b == 0)
cout << "\n";
if (i % 2 == 0)
cout << "*";
else
cout << ".";
}
cout << "\n";
}
// 2 4
// *.*.*
// .*.*.
else
{
for (int i(1); i <= a*b; i++)
{
if (i > 1 && i%b == 0)
cout << "\n";
if (i % 2 == 0)
cout << "*";
else
cout << ".";
}
cout << "\n";
}
//3 3
//*.*
//.*.
//*.*
return 0;
}