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****.

no yes no no no yes yes no yes yes yes yes yes yes no yes yes yes yes yes yes yes yes yes yes yes no no no yes yes yes yes no no yes yes yes yes yes no yes yes no no no yes yes no yes yes no no no yes yes yes yes no yes yes yes no
//Codeforces 526 //A. King of Thieves //ZeptoLab Code Rush 2015
#if 1
#include <stdio.h>

int main()
{
	int n;
	char N[101]={0};
	int i, j, k;
	int count=0;
	int check=0;
	int a;

	scanf("%d ", &n);
	gets(N);
	for(i=0; i<n; i++)
	{
		if(N[i] == '*')
			count++;
	}
	if(count >= 4)
	{
		for(j=1; j<=n/4; j++)
		{
			for(i=0; (i+j*3)<n; i++)
			{//Codeforces 526 //A. King of Thieves //ZeptoLab Code Rush 2015
#if 1
#include <stdio.h>

int main()
{
	int n;
	char N[101]={0};
	int i, j, k;
	int count=0;
	int check=0;
	int a;

	scanf("%d ", &n);
	gets(N);
	for(i=0; i<n; i++)
	{
		if(N[i] == '*')
			count++;
	}
	if(count >= 4)
	{
		for(j=1; j<=n/4; j++)
		{
			for(i=0; (i+j*4)<n; i++)
			{
				if(N[i] == '*')
				{
					count = 0;
					if((N[i] == N[i+j*1]) && (N[i] == N[i+j*2]) && (N[i] == N[i+j*3]) && (N[i] == N[i+j*4]))
					{
						printf("yes");
						return 0;
					}
				}
			}
			
		}
	}
	printf("no");
	return 0;

}
#endif

				if(N[i] == '*')
				{
					count = 1;
					if(N[i] == N[i+j*1])
						count++;
					if(N[i] == N[i+j*2])
						count++;
					if(N[i] == N[i+j*3])
						count++;
					if(count == 4)
					{
						check = 1;
						printf("yes");
						return 0;
					}
				}
			}
			
		}
	}
	printf("no");
	return 0;

}
#endif