#include <iostream>

using namespace std;

int main()
{
    unsigned int a, b, c, d;
    cin >> a >> b >> c >> d;
    unsigned count = 0;
    if (a == b || a == c || a == d)
        count++;
    if (b == c || b == d)
        count++;
    if (c == d)
        count++;
    cout << count;
    return 0;
}