A. Is your horseshoe on the other hoof?

    #include <bits/stdc++.h>

    using namespace std ;
    #define sz(s) int(s.size())
    #define all(s) s.begin() , s.end()
    #define getline(s) getline(cin >> ws, s)
    #define cin(v) for (auto& i : v) cin >> i ;
    #define pb(x) push_back(x)
    #define ll long long
    #define ull unsigned long long
    #define Mod 1'000'000'007
    #define INF 2'000'000'000
    #define Num_of_Digits(n) ((int)log10(n)+1)
    #define fixed(n) fixed << setprecision(n)
    #define imin INT_MIN
    #define imax INT_MAX
    #define Time cerr << "Time Taken: " << (float)clock() / CLOCKS_PER_SEC << " Secs" << "\n" ;


    void ABDEL3AL () {
        ios_base::sync_with_stdio(false); cin.tie(nullptr) , cout.tie(nullptr) ;
    #ifndef ONLINE_JUDGE
        freopen("input.txt" , "r" , stdin) , freopen("output.txt" , "w" , stdout) ;
    #endif
        Time
    }


    int main() {
        ABDEL3AL() ;
        int cnt = 0 ;
        vector < ll > hs(4) ;
        cin(hs) ;
        for (int i = 1; i < sz(hs); i++) {
            cnt += (hs[i - 1] == hs[i]) ;
        }
        cout << cnt ;
        return 0;
    }