#include <bits/stdc++.h>
using namespace std;
const int N = 1234567;
const int mod = 1e9 + 7;
string target = "abcdefghijklmnopqrstuvwxyz";
int main() {
  string s;
  cin >> s;
  int len = s.size();
  if (len < 26) {
    cout << -1 << endl;
  } else {
    int need = 0, last = -1;
    for (int i = 0; i < len; i++) {
      int got = s[i] - 'a';
      if (got <= need) {
        s[i] = 'a' + need;
        if (s[i] == 'y') {
          last = i;
          break;
        }
        need++;
      }
    }
    int f = 0;
    if (last == -1) {
      cout << -1 << endl;
      return 0;
    }
    for (int i = last + 1; i < len; i++) {
      if (s[i] <= 'z') {
        s[i] = 'z';
        f = 1;
        break;
      }
    }
    if (f)
      cout << s << endl;
    else
      cout << -1 << endl;
  }
  return 0;
}
