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;
   
  void __print(int x) {cout << x;}
  void __print(long x) {cout << x;}
  void __print(long long x) {cout << x;}
  void __print(unsigned x) {cout << x;}
  void __print(unsigned long x) {cout << x;}
  void __print(unsigned long long x) {cout << x;}
  void __print(float x) {cout << x;}
  void __print(double x) {cout << x;}
  void __print(long double x) {cout << x;}
  void __print(char x) {cout << '\'' << x << '\'';}
  void __print(const char *x) {cout << '\"' << x << '\"';}
  void __print(const string &x) {cout << '\"' << x << '\"';}
  void __print(bool x) {cout << (x ? "true" : "false");}
   
  template<typename T, typename V>
  void __print(const pair<T, V> &x) {cout << '{'; __print(x.first); cout << ','; __print(x.second); cout << '}';}
  template<typename T>
  void __print(const T &x) {int f = 0; cout << '{'; for (auto &i: x) cout << (f++ ? "," : ""), __print(i); cout << "}";}
  void _print() {cout << "]\n";}
  template <typename T, typename... V>
  void _print(T t, V... v) {__print(t); if (sizeof...(v)) cout << ", "; _print(v...);}
  #ifndef ONLINE_JUDGE
  #define debug(x...) cout << "[" << #x << "] = ["; _print(x)
  #else
  #define debug(x...)
  #endif
  #define int long long int 
  #define fi first
  #define se second
  #define FIO {ios::sycnt2_with_stdio(0);cin.tie(nullptr);cout.tie(nullptr);}
  #define pb push_back
  #define all(x) (x).begin(), (x).end()
  #define rall(x) (x).rbegin(), (x).rend()
  #define forn(i, n) for (int i = 0; i < (int)(n); ++i)
  #define for1(i, n) for (int i = 1; i <= (int)(n); ++i)
  #define ford(i, n) for (int i = (int)(n) - 1; i >= 0; --i)
  #define all(x) (x).begin(), (x).end()
  #define pow10(n) stoll("1"+string(n,'0'))
  //fill(all(arr),1)
  //if(map.count(key)){}
  //bitset<20>(n);
  //int mini=min({a,b,c,d,e});
   
  typedef pair<int, int> pii;
  typedef vector<int> vi;
  typedef vector<pii> vpi;
  typedef vector<vi> vvi;
  typedef long long ll;
  typedef vector<ll> vll;
  typedef vector<vll> vvll;
  typedef long double ld;
  int32_t main()
  {
    string s,t;
    cin>>s>>t;
    int cnt=0;
    forn(i,s.size())
    {
      if(s[i]!=t[i])cnt++;
    }
    cout<<cnt;
  }