#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long int n, m = 0, x, k = 97, d, i, index, flag, count = 0, result, odd,
                   even, sum = 0, temp;
  string str;
  cin >> str;
  n = str.size();
  for (i = 0; i < n; i++) {
    if (str[i] <= k) {
      str[i] = k;
      if (k == 122) {
        m = 1;
        break;
      }
      k++;
    }
  }
  if (m == 1)
    cout << str << endl;
  else
    cout << -1 << endl;
  return 0;
}
