#include <iostream>
#include <cstring>
using namespace std;

int main()
{
    setlocale(LC_ALL,"");
    char str[256];
    cout << "Введите строку : ";
    cin.getline(str,256);
    double average, summa = 0 , count = 0;
    char* ptr=strtok(str," .,!?");
    do {
        summa = summa +  strlen(ptr);
        count += 1;
    }
    while(ptr=strtok(NULL," .,!?"));
    average = summa / count ;
    cout << "Средняя длинна слов равна : " << average << endl;
}