#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int c = 0;
  int u = 'a';
  for (int i = 0; i < s.length(); i++) {
    if (c >= 26) break;
    if (s[i] <= u) {
      s[i] = u;
      c++;
      u++;
      if (u > 'z') break;
    }
  }
  if (c >= 26)
    cout << s;
  else
    cout << "-1";
  return 0;
}
