hi everyone, can someone make this code easier?

Code:
#include <iostream>
#include <string>
#include <cctype>

using namespace std;

int main() 
{
    int numOfChar[26];
    int sum = 0;
    string lowerCase;
    string name;
  
    lowerCase = "", name = "";
    
    // initialise array of string to 0.
    for (int i = 0; i < 26; i++)
    
       numOfChar[i] = 0; 
    
    // Prompt user input    
    cout << "name please: ";
    cin >>name;    

    // convert to lower case

    for (int i = 0; i < name.length(); i++)
    
        lowerCase += tolower(name[i]); 
        
    //

    for (int i = 0; i < lowerCase.length(); i++) 
    {
      if (lowerCase[i] - 'a' < 26 && numOfChar[lowerCase[i] - 'a'] == 0) 
      {
        numOfChar[lowerCase[i] - 'a'] = 1;
      }
    }
    
    //

    for (int i = 0; i < 26; i++)
      sum += numOfChar[i];

   cout << "\nYou have " << sum << " different letters in your string.\n" 
        << endl;
        
   system("pause");
   return 0;
}