count even length words in vectors [migrated]

I have 2 problems.

1) cout << v_setir.capacity(); is not returns the correct number.

2) I want to count of the words which lengths are even. and I should do it with vectors.

Here is my codes:

#include <iostream>
#include <vector>
#include <sstream>

using namespace std;

int main()
{
    int say = 0;

    cout << "Setiri daxil edin: ";
    string setir;
    getline(cin, setir);

    vector<string> v_setir;
    string ifadeler;
    istringstream yig(setir);

    while (yig >> ifadeler)
        v_setir.push_back(setir);

    // First problem
    cout << v_setir.capacity() << endl;

    // Second problem
/*  for (size_t i = 0; i < v_setir.capacity(); i++)
    {
        if (v_setir[i].size() % 2 == 0)
            say += 1;
    }
    cout << "Uzunlugu cut olan sozerin sayi: " << say << endl;*/

    return 0;
}

For example, if I enter this string line it returns "6" (why I don't know):

hi hello how are you

What is wrong? my brain stopped and I couldn't determine what is the wrong in my code and/or algorithm.

Please, help me to solve these problems.

Best regards.