#include <iostream>
#include <string>
using namespace std;

int main() {
  string s;
  while ((cin >> s) && (s != "end")) {
    int v = 0;
    for (int i = 0; i < int(s.size()); i++) {
      int c = (s[i] >= '0' && s[i] <= '9'? s[i] + 0 - '0' :
               s[i] >= 'A' && s[i] <= 'Z'? s[i] + 10 - 'A' : s[i] + 36 - 'a');
      v = (62*v + c) % 61;
    }
    cout << (v == 0? "yes" : "no") << endl;
  }
  return 0;
}