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++ (Clang 10.0.0) (judge verdict: Accepted)

#include <iostream>
using  namespace std;
#define ll      long long int
#define pai     pair<int,int>
#define vi      vector<int>
#define vd      vector<double>
#define vs      vector<string>
#define vp      vector< pair <string,int> >
#define mpi     map<int,int>
#define mps     map<char,int>
#define sti     stack<int>
#define stc     stack<char>
#define sei     set<int>
#define ses     set<string>
#define multii  multiset<int>
#define forn(i,n)    for (int i = 0; i < n; i++)
#define fork(i,k,n)  for (int i = k; i <= n; i++)
#define forkr(i,k,n) for (int i = k; i >= n; i--)

 int main()
{
 ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
string s,t;
cin>>s;
cin>>t;
ll c=0;
forn(i,s.size()){
if(s[i]!=t[i]){
    c++;
}

}
cout<<c<<endl;

}