526A - King of Thieves

#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<queue>
#include<vector>
#include<stack>

using namespace std;

const int MAX = 1000;

char s[MAX];

int main(){
int n;
while (scanf("%d%s",&n,s) != EOF){
int ok = 0,len = n;
for (int l = 1; l<len; l++){
for (int i = 0; i<len; i++){
int j, cnt = 0;
for (j = i; j<len; j+=l){
if (s[j] == '*'){
cnt++;
}
else{
break;
}
}
if (cnt >= 5){
ok = 1;
break;
}
}
if (ok) break;
}
if (ok) printf("yes\n");
else printf("no\n");
}
return 0;

}