You are given a string s consisting of |s| small english letters.

In one move you can replace any character of this string to the next character in alphabetical order (a will be replaced with b, s will be replaced with t, etc.). You cannot replace letter z with any other letter.

Your target is to make some number of moves (not necessary minimal) to get string abcdefghijklmnopqrstuvwxyz (english alphabet) as a subsequence. Subsequence of the string is the string that is obtained by deleting characters at some positions. You need to print the string that will be obtained from the given string and will be contain english alphabet as a subsequence or say that it is impossible.


-----Input-----

The only one line of the input consisting of the string s consisting of |s| (1 ≤ |s| ≤ 10^5) small english letters.


-----Output-----

If you can get a string that can be obtained from the given string and will contain english alphabet as a subsequence, print it. Otherwise print «-1» (without quotes).


-----Examples-----
Input
aacceeggiikkmmooqqssuuwwyy

Output
abcdefghijklmnopqrstuvwxyz

Input
thereisnoanswer

Output
-1

Difficulty: interview

Starter code:

Solutions:
s = list(input())
target = 'abcdefghijklmnopqrstuvwxyz'
ind_t = 0
ind_s = 0
while ind_s < len(s) and ind_t < 26:
  if ord(s[ind_s]) <= ord(target[ind_t]):
    s[ind_s] = target[ind_t]
    ind_t += 1
    ind_s += 1
  else:
    ind_s += 1
if ind_t == 26:
  print(''.join(s))
else:
  print(-1)


a = list(input())
i = 0
k = 0
l = len(a)
while i<l:
	if a[i]<=chr(97+k):
		if k<26:
			a[i] = chr(97+k)
			k+=1
	i+=1
if k==26:
	print (''.join(a))
else:
	print (-1)

s = list(input())
st = 'a'
for i in range(len(s)):
    if (s[i] <= st):
        s[i] = st
        st = chr(ord(st) + 1)
    if st > 'z':
        break
if (st <= 'z'):
    print(-1)
else:
    print(*s,sep = '')

s = input()
t = 97
o = ''
for i in s:
    if ord(i)<= t and t <= 122:
        o += chr(t)
        t += 1
    else:
        o += i
if t != 123:print(-1)
else:print(o)


s = list(input())

a = "abcdefghijklmnopqrstuvwxyz"

i = 0
j = 0

while i < len(a) and j < len(s):
	if s[j] <= a[i]:
		s[j] = a[i]
		i += 1
	j += 1

if i == len(a):
	print("".join(s))
else:
	print(-1)


s = input()
n = len(s)
L = list(s)
S = 'abcdefghijklmnopqrstuvwxyz'
ind = 0
for i in range(n):
    if (ind < 26 and s[i] <= S[ind]):
        L[i] = S[ind]
        ind += 1
        

    
ans = ""
for item in L:
    ans += item

if (ind >= 26):
    print(ans)
else:
    print(-1)
    


s=input()
arr=[]
for i in s:
    arr.append(i)
c='a'
d=0
for i in range(len(arr)):
    if arr[i]<=c:
        arr[i]=c
        if c=='z':
            d=1
            break
        c=chr(ord(c)+1)

if d==0:
    print(-1)
else:
    print(*arr,sep='')


s=input()
newst=[]

curr='a'

for k in s:
	if curr>=k and curr<='z':
		newst.append(curr)
		curr=chr(ord(curr)+1)
	else:
		newst.append(k)
if curr>'z':
	for k in newst:
		print(k,end='')
	print()
else:
	print(-1)

import sys
# from io import StringIO
# sys.stdin = StringIO(open(__file__.replace('.py', '.in')).read())

s = list(input())

if len(s) < 26:
    print(-1)
    return

al = list('abcdefghijklmnopqrstuvwxyz')
i = 0
for j in range(len(s)):
    c = s[j]
    if ord(c) <= ord(al[i]):
        s[j] = al[i]
        i += 1
        if i == 26:
            break

if i >= 26:
    print(''.join(s))
else:
    print(-1)

s=input()
ans=s+''
l=len(s)
a='abcdefghijklmnopqrstuvwxyz'
i=0
for j in range(26):
    while s[i]>a[j]:
        i+=1
        if i==l:
            print(-1)
            return
    ans=ans[:i]+a[j]+ans[i+1:]
    i+=1
    if j!=25 and i==l:
        print(-1)
        return
print(ans)


s = list(input())
ch = 'a'
for i in range(len(s)):
    if s[i] <= ch:
        s[i] = ch
        if ch == 'z':
            ans = ''
            for i in range(len(s)):
                ans += s[i]
            print(ans)
            break
        ch = chr(ord(ch) + 1)
else:
    print(-1)

s = str(input())

current = ord('a')

n = len(s)

ans = ''

for i in range(n):
    if ord(s[i]) <= current and current < 123:
        ans += chr(current)
        current += 1
    else: ans += s[i]
    
if current == 123: print(ans)

else: print(-1)

#!/usr/bin/env python3

import sys

s = sys.stdin.readline().strip()
alph = 'abcdefghijklmnopqrstuvwxyz'

res = []
ia = 0
done = False

for i, c in enumerate(s):
	if c <= alph[ia]:
		res.append(alph[ia])
		ia += 1
		if ia == len(alph):
			done = True
			idone = i
			break
	else:
		res.append(c)

if done:
	print(''.join(res) + s[idone +1:])
else:
	print ('-1')



s = list(input())
want = "abcdefghijklmnopqrstuvwxyz"

j = 0
for i in range(len(s)):

	if j >= 26:
		break

	if s[i] <= want[j]:
		s[i] = want[j]
		j += 1


if j < 26:
	print(-1)
else:
	ans = "".join(s)
	print(ans)


from string import ascii_lowercase
s = list(input())
symbs = ascii_lowercase

cursymbol = 0
for d in range(len(s)):
    if s[d] <= ascii_lowercase[cursymbol]:
        s[d] = ascii_lowercase[cursymbol]
        if ascii_lowercase[cursymbol] == 'z':
            print(''.join(s))
            return
        cursymbol += 1
print(-1)


def solve():
    S = input()
    counter = 97
    res = ""
    for s in list(S):
        s = ord(s)
        if counter >= 123:
            res += chr(s)
            continue

        if s <= counter:
            res += chr(counter)
            counter += 1
        else:
            res += chr(s)

    if counter == 123:
        print(res)
    else:
        print(-1)

def __starting_point():
    solve()



__starting_point()

s = input()
k = 0
n = 97
a = []
for i in s:
    a.append(i)
for i in range(len(s)):
    if ord(a[i]) <= n:
        a[i] = chr(n)
        n+=1
        k+=1
    if k == 26:
        break
if k < 26:
    print(-1)
else:
    print(*a,sep = '')

s=input()
alpha="abcdefghijklmnopqrstuvwxyz"
c=0
cnt=0
ans=""
while cnt<len(s) and c<26:
    if (ord(s[cnt])-ord('a'))<=c:
        ans+=alpha[c]
        c+=1
    else:
        ans+=s[cnt]
    cnt+=1
if c==26:
    ans+=s[cnt:]
    print(ans)
else:
    print(-1)


s = [c for c in input()]

current_char = 97

for i in range(len(s)):
    if current_char == 123:
        continue
    elif ord(s[i]) <= current_char:
        s[i] = chr(current_char)
        current_char += 1

if current_char < 123:
    print(-1)
else:
    print(''.join(s))


s = list(input())
if len(s) < 26 :
    print(-1)
    return

alpha = 'abcdefghijklmnopqrstuvwxyz'
cidx = 0

for i in range(len(s)) :
    if s[i] <= alpha[cidx] :
        s[i] = alpha[cidx]
        cidx += 1
    if cidx == 26 :
        print(''.join(s))
        return
else :
    print(-1)

import math

s = input()
alf = "abcdefghijklmnopqrstuvwxyz"
n = -1

def con_str(string, ch, i):
    return string[:i] + ch + string[i+1:]

for i in alf:
    flag = False
    for j in range(n+1, len(s)):
        if s[j]<=i:
            n = j
            s = con_str(s, i, j)
            flag = True
            break
    if not(flag):
        print(-1)
        return
print(s)