#include <bits/stdc++.h>
using namespace std;
inline void File() {
  freopen(".in", "r", stdin);
  freopen(".out", "w", stdout);
}
inline void read(int &x) {
  int p = 1;
  x = 0;
  char c = getchar();
  while (!isdigit(c)) {
    if (c == '-') p = -1;
    c = getchar();
  }
  while (isdigit(c)) {
    x = (x << 3) + (x << 1) + (c ^ '0');
    c = getchar();
  }
  x *= p;
}
char s[100010];
int main() {
  scanf("%s", s + 1);
  int l = strlen(s + 1);
  if (l < 26) {
    puts("-1");
    return 0;
  }
  int cnt = 0;
  for (register int i = 1; i <= l; i++) {
    if (s[i] <= (cnt + 'a')) {
      s[i] = cnt + 'a';
      cnt++;
    }
    if (cnt == 26) break;
  }
  if (cnt != 26) {
    puts("-1");
    return 0;
  } else
    cout << s + 1 << endl;
  return 0;
}
