#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int n = s.length();
  if (n < 26)
    cout << -1;
  else {
    string temp = "";
    int curr = 0, idx;
    for (int i = 0; i < n; i++) {
      idx = (int)(s[i] - 'a');
      if (idx <= curr && curr < 26) {
        temp += (char)(curr + 'a');
        curr++;
      } else
        temp += s[i];
    }
    if (curr > 25)
      cout << temp;
    else
      cout << -1;
  }
}
