/*
 * @topic T00299 Apr 11 -- character classification
 * @brief The program demonstrates <tt>isdigit</tt>, <tt>tolower</tt>, and <tt>switch</tt>
*/

#include <iostream>
using std::cin;
using std::cout;
int main()
{
    for(;;) {
        char ch = 0;
        cin >> ch; // get character from the user
        if ( !isdigit( ch ) ) {
            // this is not a digit
            cout << tolower( ch ); // convert to lowercase and display
        }

        // If not using isdigit() we could try this switch statement:
        switch( ch ) {
        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
            // this is a digit:
            continue;
        default:
            // this is not a digit:
            cout << ch;
        }
    }//for
    return 0;
}