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 Scala (2.13.1) (judge verdict: Accepted)

object methods {
  def solver: Unit = {

    val tempList: Seq[Seq[String]] = {
      for(line <- io.Source.stdin.getLines()) yield {
        line.split(' ').toSeq
      }
    }.toSeq

    val S: String = tempList(0)(0)
    val T: String = tempList(1)(0)

    var i = 0
    var notSame: Int = 0
    while(i < S.size){
      if(S(i) != T(i)) notSame += 1
      i += 1
    }

    println(notSame)

  }
}

object Main extends App {
  methods.solver
}