func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int s1, s2, s3, s4;     cin >> s1 >> s2 >> s3 >> s4;     unordered_set<int> s;     s.insert(s1);     s.insert(s2);     s.insert(s3);     s.insert(s4);     int si = s.size();     if (si == 4)       cout << 0;     else if (si == 3)       cout << 1;     else if (si == 2)       cout << 2;     else       cout << 3;     return 0;   }   