#include <bits/stdc++.h>
using namespace std;
string s = "abcdefghijklmnopqrstuvwxyz";
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  string str;
  cin >> str;
  long long int cnt = 0;
  long long int len = str.length();
  for (long long int i = 0, j = 0; i < len; i++) {
    if (j >= 26) break;
    if (str[i] <= s[j]) {
      str[i] = s[j];
      cnt++;
      j++;
    }
  }
  if (cnt == 26)
    cout << str << endl;
  else
    cout << -1 << endl;
}
