#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long t;
  cin >> t;
  while (t--) {
    string s;
    cin >> s;
    long long arr[s.size()];
    for (long long i = 0; i < s.size(); i++) {
      s[i] = s[i] - 'a';
      arr[i] = s[i];
    }
    set<long long> st;
    sort(arr, arr + (s.size()));
    st.insert(arr[0]);
    for (long long i = 1; i < s.size(); i++) {
      if (arr[i] == arr[i - 1] + 1) st.insert(arr[i]);
    }
    if (st.size() == s.size())
      cout << "yes" << endl;
    else
      cout << "no" << endl;
  }
  return 0;
}
