// Ex3_01.cpp
  // A nested if demonstration
  include <iostream>
  
  using std::cin;
  using std::cout;
  using std::endl;
  
  int main()
  {
     char letter = 0;                      // Store input in here
  
     cout << endl
          << "Enter a letter: ";           // Prompt for the input
     cin >> letter;                        // then read a character
  
     if(letter >= 'A')                     // Test for 'A' or larger
        if(letter <= 'Z')                  // Test for 'Z' or smaller
        {
           cout << endl
                << "You entered a capital letter."
                << endl;
           return 0;
        }
  
     if(letter >= 'a')                     // Test for 'a' or larger
        if(letter <= 'z')                  // Test for 'z' or smaller
        {
           cout << endl
                << "You entered a small letter."
                << endl;
           return 0;
        }
  
     cout << endl << "You did not enter a letter." << endl;
     return 0;
  }