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)

#include<bits/stdc++.h>
using namespace std;
#define pb push_back
typedef long long int ll;
const int N = 1e5 + 5;
//const int INF = 1e9 + 5;
int a[N];
void solve_test_case(){
	string s,t;
	cin>>s>>t;
	int c = 0;
	for(int i = 0;s[i];){
		
		for(int j = 0;t[j];++j){
			if(s[i] != t[j])
				c++;
			i++;
		}
	}		
	cout<<c<<"\n";
}
 
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	int t = 1;
	// cin>>t;
	for(int i = 0;i < t;++i){
		solve_test_case();
	}
}