Problem:
Score : 200 points

Problem Statement

Given are strings S and T. Consider changing S to T by repeating the operation below. Find the minimum number of operations required to do so.

Operation: Choose one character of S and replace it with a different character.

Constraints

S and T have lengths between 1 and 2\times 10^5 (inclusive).

S and T consists of lowercase English letters.

S and T have equal lengths.

Input

Input is given from Standard Input in the following format:

S
T

Output

Print the answer.

Sample Input 1

cupofcoffee
cupofhottea

Sample Output 1

4

We can achieve the objective in four operations, such as the following:

First, replace the sixth character c with h.

Second, replace the eighth character f with t.

Third, replace the ninth character f with t.

Fourth, replace the eleventh character e with a.

Sample Input 2

abcde
bcdea

Sample Output 2

5

Sample Input 3

apple
apple

Sample Output 3

0

No operations may be needed to achieve the objective.

Solution in Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

import java.util.*;
public class Main{
	public static void main(String args[]){
      Scanner sc = new Scanner(System.in);
    	String s = sc.nextLine();
      String s1 = sc.nextLine();
      String res = "";
      int count =0;
      for(int i=0;i<s.length();i++){
      	if(s.charAt(i)!=s1.charAt(i)){
          res+=s.charAt(i);
          count++;
        }
        else{
       		res+=s.charAt(i); 
        }
      }
      System.out.println(res);
      
    }
}