#include <bits/stdc++.h>
using namespace std;
long long int mod = 1000000007;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int t = 1;
  while (t--) {
    string s;
    cin >> s;
    int n = s.size();
    if (n < 26)
      cout << "-1";
    else {
      char ch = 'a';
      int f = 0;
      for (int i = 0; i < n; i++) {
        if (s[i] <= ch) {
          s[i] = ch;
          if (ch == 'z') {
            f = 1;
            break;
          } else
            ch++;
        }
      }
      if (f == 0)
        cout << "-1";
      else
        cout << s;
    }
  }
}
