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

long long a[4], w;

int main()
{
    cin >> a[0] >> a[1] >> a[2] >> a[3];

    sort(a, a + 4);

    for(int i = 0; i < 4; i++) if(a[i] == a[i + 1]) w++;

    cout << w;
}