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# (Mono-mcs 6.8.0.105) (judge verdict: Wrong Answer)

using System;


namespace SoloLearn
{
    class Program
    {
        static void Main(string[] args)
        {    
            string S = "cupofcoffee";
            string T = "cupofhottea";
            int count = 0;
            
          for(int i=0; i<S.Length; i++)
          {
             if(S[i]!=T[i])
                count++;
          }
          
          Console.Write(count);
        }
    }
}