#include <bits/stdc++.h>
using namespace std;
int main() {
  int j, k, pnjg, m, d;
  string input, t;
  cin >> input;
  t = "";
  for (int i = 'a'; i <= 'z'; i++) t.push_back(i);
  k = 0;
  pnjg = input.length();
  for (int i = 0; i < pnjg; i++) {
    if (k == 26) {
      cout << input;
      return 0;
    }
    if (t[k] == input[i])
      k++;
    else {
      if (t[k] > input[i]) input[i] = t[k], k++;
    }
  }
  if (k == 26)
    cout << input;
  else
    cout << "-1";
  return 0;
}
