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 JavaScript (Node.js 12.16.1) (judge verdict: Accepted)

let main = (input) => {
    let usrInput = input.split(/\n/)
    let time = 0
    if (usrInput[0] !== usrInput[1]) {
        for (let index = 0; index < usrInput[0].length; index++) {
            if (usrInput[0][index] != usrInput[1][index]) {
                time++
            }
        }
    }
    console.log(time)
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'))