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 C (GCC 9.2.1) (judge verdict: Accepted)

//https://atcoder.jp/contests/abc172/tasks/abc172_b


#include<stdio.h>     //AA06( 23/ 07/ 20) If u see my code, Have a Good Day! (^_^)
#include<string.h>
#define LENTH 200001

int main()
{
    char S[LENTH], T[LENTH];

    int i, count = 0;

    scanf("%s%s", S, T);

    for(i = 0; i < strlen(S); ++i) {

        if(S[i] != T[i])
            count++;
    }

    printf("%d\n", count);

    return 0;
}