int main()
{ char c, b;
  c=getchar();
  while (c!=EOF && b!=EOF)
	  {b=getchar();
	   if (c==b)
		{putchar(c);
		 putchar(b);
		 c=getchar();
		 while (c!=' ' && c!=EOF)
			 {putchar(c);
			  c=getchar();
			 }
		 putchar(' ');
		}
	   c=getchar();
	  }
  getch();
	return 0;