#include <bits/stdc++.h>
using namespace std;
int main() {
  string temp;
  getline(cin, temp);
  string alphabet = "abcdefghijklmnopqrstuvwxyz";
  string result = "";
  int i = 0;
  int t = 0;
  if (temp.size() < 26) {
    cout << -1;
    return 0;
  }
  while (t < temp.size() && i < alphabet.size()) {
    if (temp[t] <= alphabet[i]) {
      result += alphabet[i];
      i++;
      t++;
    } else {
      result += temp[t];
      t++;
    }
  }
  if (i == 26) {
    cout << result + temp.substr(t);
    return 0;
  }
  cout << -1;
  return 0;
}
