func_code_string: #include <bits/stdc++.h>   using namespace std;   const double PI = acos(-1.0);   int main() {     int s1, s2, s3, s4;     int a[4];     cin >> a[0] >> a[1] >> a[2] >> a[3];     int i, j, k = 0;     sort(a, a + 4);     j = a[0];     for (i = 1; i < 4; ++i) {       if (j == a[i]) {         k++;       } else         j = a[i];     }     cout << k;     return 0;   }   