#include <bits/stdc++.h>
using namespace std;
int main() {
  cout.precision(17);
  string s;
  cin >> s;
  int j = 0;
  bool x = 0;
  string answer = "";
  bool p = 1;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] - 'a' > j) {
      answer += s[i];
    } else {
      if (p == 1) {
        char g;
        g = j + 'a';
        answer += g;
        j++;
      } else {
        answer += s[i];
      }
    }
    if (j > 25) {
      p = 0;
      x = 1;
    }
  }
  if (x == 0) {
    cout << "-1";
  } else {
    cout << answer;
  }
  return 0;
}
