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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
#include <bits/stdc++.h>
unsigned char get_num(void) {
  char tmp[8];
  fgets(tmp, 8, stdin);
  return atoi(tmp);
}
int main(void) {
  unsigned char n;
  n = get_num();
  char str[n];
  unsigned char jmp_lim = n - 4;
  unsigned char jump_size;
  scanf("%s", str);
  for (jump_size = 1; jump_size <= jmp_lim; jump_size++) {
    unsigned char start_lim = n - jump_size;
    unsigned char start_dot;
    for (start_dot = 0; start_dot < start_lim; start_dot++) {
      if (str[start_dot] == 42) {
        unsigned char dot = start_dot;
        unsigned char yes = 0;
        while (dot + jump_size <= n) {
          dot = dot + jump_size;
          if (str[dot] == 42) {
            yes++;
          } else {
            break;
          }
        }
        if (yes == 4) {
          printf("yes");
          return 0;
        }
      }
    }
  }
  printf("no");
  return 0;
}
