228A - Is your horseshoe on the other hoof?

#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;


int main() {

    int s[4];
    int ans = 0;
    cin >> s[0] >> s[1] >> s[2] >> s[3];
    sort(s, s + 4);
    for(int i = 0; i < 3; ++i) {
        if(s[i] == s[i+1]) {
            ans++;
        }
    }
    cout << ans << endl;
    return 0;
}