ZeptoLab Code Rush 2015 A. King of Thieves

# include<cstdio>
# include<iostream>

using namespace std;

# define MAX 123

char s[MAX];
int a[MAX];

int main(void)
{
int n;
scanf("%d",&n);
scanf("%s",s+1);
int flag = 0;
for ( int i = 1;i <= n;i++ )
{
for ( int j = 1;j <= 100;j++ )
{
if ( s[i]=='*'&&s[i+j]=='*'&&s[i+2*j]=='*'&&s[i+3*j]=='*'&&s[i+4*j]=='*' )
{
flag = 1;
break;
}
}
if ( flag )
break;
}
if ( flag )
cout<<"yes"<<endl;
else
cout<<"no"<<endl;

return 0;
}