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: Runtime Error)

#include <stdio.h>
int main(){
char *s,*t;
int i=0,l=0;
int count=0;
while(i <= 200000){
scanf("%c",s);
s++;
if(s == NULL)break;
i++;}
while(l <= i ){
scanf("%c",t);
t++;
l++;}
s=0;
t=0;
if(*s != *t) {count++;
	     s++;
	     t++;}

if(i<count) printf("%d",i);
else printf("%d",count);
}