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)

//verma_ankit484

#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

#define int long long
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define endl "\n"
#define pb push_back
const int mod = (int) 1e9+7;

using namespace std;
//using namespace __gnu_pbds;

//#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>


int32_t main() {
  IOS
  #ifdef AV
  freopen("input.txt", "r", stdin);
  #endif
  string s, t;
  cin >> s >> t;
  int ans = 0;
  for (int i = 0; i < (int)s.length(); i++) {
    if (s[i] != t[i]) ans++;
  }
  cout << ans << endl;
  return 0;
}