Maximum by Single Digit Replacement

Maximum by Single Digit Replacement: Two integers M and N are passed as the input to the program. The program must print the maximum value of M obtained by replacing exactly one digit in M by a digit from N.

Boundary Condition(s):
1 <= Number of digits in M <= 100
1 <= Number of digits in N <= 10

Input Format:
The first line contains M and N separated by space(s).

Output Format:
The first line contains the maximum value of M.

Example Input/Output 1:
Input:
56120 21

Output:
56220

Explanation:
The maximum value is obtained by replacing 1 in 56120 by 2.
Any other replacements would give smaller values.

Example Input/Output 2:
Input:
895496223 5

Output:
895596223

Maximum by Single Digit Replacement in Java

import java.util.*;
public class Hello {
    public static void main(String[] args)
    {
Scanner sc=new Scanner(System.in);
String f=sc.next();
String s=sc.next();
char ff[]=f.toCharArray();
char ss[]=s.toCharArray();
int maxi=0;
for(int i=0;i<ss.length;i++)
{
    if(Integer.parseInt(String.valueOf(ss[i]))>maxi)
    {
        maxi=Integer.parseInt(String.valueOf(ss[i]));
    }
}
int fl=0;
for(int i=0;i<ff.length;i++)
{
    if(maxi>Integer.parseInt(String.valueOf(ff[i])))
    {
        ff[i]=(char)(maxi+'0');
        break;
    }
}
System.out.println(String.valueOf(ff));
}
}