#include <bits/stdc++.h>
int mod = 1073741824;
using namespace std;
int main() {
  string s;
  cin >> s;
  int n;
  n = s.length();
  if (n < 26) {
    cout << "-1" << endl;
  } else {
    int curr = -1;
    for (int i = 0; i < n; i++) {
      if (s[i] - 'a' == curr + 1) {
        curr = curr + 1;
      } else if (s[i] - 'a' == curr) {
        s[i] = s[i] + 1;
        curr = curr + 1;
      } else if (s[i] - 'a' < curr) {
        s[i] = 'a' + curr + 1;
        curr = curr + 1;
      }
      if (curr == 25) {
        break;
      }
    }
    if (curr == 25) {
      cout << s << endl;
    } else {
      cout << "-1" << endl;
    }
  }
}
