A. Distinct Digits （ Codeforces Round #589 (Div. 2) ）

You have two integers ll and rr. Find an integer xx which satisfies the conditions below:

• l≤x≤rl≤x≤r.
• All digits of xx are different.

If there are multiple answers, print any of them.

Input

The first line contains two integers ll and rr (1≤l≤r≤1051≤l≤r≤105).

Output

If an answer exists, print any of them. Otherwise, print −1−1.

Examples

input

Copy

121 130

output

Copy

123

input

Copy

98766 100000

output

Copy

-1

Note

In the first example, 123123 is one of the possible answers. However, 121121 can't be the answer, because there are multiple 11s on different digits.

In the second example, there is no valid answer.

bool judge(lli num)
{
    int a[10]={0};
    while(num)
    {
        if( a[ num%10 ]  )
            return 0;
        else 
            a[ num%10 ] = 1;
        num /= 10;
    }
    return 1;
}
int main()
{
    lli l,r;
    cin>>l>>r;
    for(lli i=l;i<=r;i++)
    {
        if(judge(i)){
            cout<<i<<endl;return 0;
        }
 
    }
    cout<<"-1"<<endl;
 
 
    return 0;
}