#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  int n, big = 0, small = 1000;
  string s;
  int a[123] = {0};
  bool ok = false;
  cin >> n;
  for (int i = 0; i < n; i++) {
    int a[123] = {0};
    cin >> s;
    sort(s.begin(), s.end());
    for (long long t = 0; t < s.size(); t++) {
      a[s[t]]++;
      if (s[t] < small) {
        small = s[t];
      }
      if (s[t] > big) {
        big = s[t];
      }
    }
    for (long long k = small; k <= big; k++) {
      if (s.find(k) == -1) {
        ok = true;
      } else if (a[k] > 1) {
        ok = true;
      }
    }
    if (ok == true) {
      cout << "no";
    } else {
      cout << "yes";
    }
    cout << endl;
    ok = false;
    big = 0, small = 1000;
  }
  return 0;
}
