#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  string s;
  cin >> s;
  long long int n = s.length();
  if (n < 26) {
    cout << -1;
    return 0;
  }
  bool ok = false;
  char curr = 'a';
  bool last_filled = false;
  for (__typeof(n) i = (0) - ((0) > (n)); i != (n) - ((0) > (n));
       i += 1 - 2 * ((0) > (n))) {
    if (s[i] <= (int)curr) {
      s[i] = curr;
      if (curr == 'z') {
        last_filled = true;
        break;
      }
      curr++;
    }
  }
  if (last_filled)
    cout << s;
  else
    cout << -1;
  return 0;
}
