#include <iostream>
#include <string>

using namespace std;

int main() {
     string hello = {"Hello World 123 $%!"};
     int pos;
     string first,
            second;
     int i;

     cout << "The string is \"" << hello << '"' << endl;
     cout << "It contains " << hello.size() << " characters." << endl;

     pos = hello.find(" ");
     cout << "The first space is at position " << pos << endl;

     cout << endl;

     first = hello.substr(0, pos);
     second = hello.substr(pos+1, string::npos);
     cout << "The first string is \"" << first << '"' << endl;
     cout << "The second string is \"" << second << '"' << endl;

     cout << endl << endl;
     i = 0;
     while (i < hello.size() ) {
         //cout << i << " " << hello[i] << endl;
         cout << i << " " << hello.at(i) << endl;
         i++;
     }
     cout << endl << endl;

     i = 0;
     while(i < hello.size()) {
         hello.at(i) = toupper(hello.at(i));
         i++;
     }

     i = hello.size() - 1;
     while (i >= 0 ) {
         cout << hello[i];
         i--;
     }

     cout << endl << endl;


     return 0;
}