#include <iostream>
#include <string>
using namespace std;
int main()
{
	string str;
   cout<<"Enter string"<<endl;
   getline(cin,str);
    const int len = str.length();
    for (int i = 1; i<len; i += 2)
    {
        cout << str[i];
    }
    for (int i = len % 2 ? len - 1 : len - 2; i >= 0; i -= 2)
    {
        cout << str[i];
    }
    cout << endl;
     system("pause");
    return 0;
}





#include <iostream>
#include <string>
using namespace std;
int main()
{
	string str,slovo;
	int s=0;
	string::size_type k=0,pos=0;
	string razdel=",.:;!? ";
	cout<< "Enter string"<<endl;
	getline(cin,str);
    k=str.find_first_of(razdel,pos);
	while (k!=string::npos)
	{slovo=str.substr(pos,k-pos);
	if (ispunct(str[k])) pos=k+2; else pos=k+1;
	if (slovo[0]==slovo[slovo.length()-1]) s++; 
	k=str.find_first_of(razdel,pos)
	}