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 <iostream>
#include<vector>
#include<map>
#include<set>
#include<string>
#include<algorithm>
#include<math.h>
#include<bits/stdc++.h>
#include<cmath>
#include<iomanip>
#include<queue>
#include<string>
using namespace std;

const double PI  =3.141592653589793238463;
#define pb push_back
#define pf push_front
#define sz(v)  ((int)(v).size());
#define all(v) ((v).begin()),((v).end())
typedef unsigned long long ull;
typedef long long ll;

typedef vector<int> vi;
typedef pair<int,int> pi;
//2 7 3 4 9

void printVec(vi v1)
{
    for(int i=0; i<v1.size(); i++)
        cout<<v1[i]<<" ";
    cout<<endl;
}
int main()
{
    ios::sync_with_stdio(false);
    cout.tie(NULL);
    cin.tie(NULL);
string s;cin>>s;
string t;cin>>t;
ll ctr=0;
for(ll i=0;i<s.length();i++){
    if(s[i]!=t[i]){
        ctr++;
    }
}
cout<<ctr;
    return 0;

}