#include <bits/stdc++.h>
using namespace std;
long long mod = 1e9 + 7;
void boost() {
  std::ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
}
int main() {
  string s;
  cin >> s;
  int l = s.length();
  if (l < 26) {
    cout << -1 << "\n";
  } else {
    char baki = 'a';
    for (int i = 0; i < l; i++) {
      if (s[i] <= baki) {
        s[i] = baki;
        baki++;
      }
      if (baki > 'z') break;
    }
    if (baki > 'z')
      cout << s << "\n";
    else
      cout << -1 << "\n";
  }
  return 0;
}
