#include <bits/stdc++.h>
using namespace std;
void Debug(vector<int> v) {
  for (int i : v) {
    cerr << i << " ";
  }
}
void Debug(int a[]) {
  for (int i = 0; i < 5; i++) {
    cerr << a[i] << " ";
  }
}
void Debug(int a) { cerr << a; }
void Debug(string a) { cerr << a; }
void Debug(long long a) { cerr << a; }
void Debug(unsigned long long a) { cerr << a; }
void Debug(float a) { cerr << a; }
void Debug(double a) { cerr << a; }
void Debug(char a) { cerr << a; }
int32_t main() {
  string s;
  cin >> s;
  int64_t n = s.length();
  if (n < 26) {
    cout << -1;
    return 0;
  }
  char check = 'a';
  int64_t cnt = 0;
  for (int64_t i = 0; i < n; i++) {
    if (s[i] <= check) {
      cnt++;
      s[i] = check;
      check++;
    }
    if (cnt >= 26) {
      cout << s;
      return 0;
    }
  }
  cout << -1;
  return 0;
}
