static govno

#include <bits/stdc++.h>
using namespace std;

class compute {
private:
    static int a;
public:
    static int get();
    static int get(int x);
};

int compute::a{};

int compute::get() {
    return a;
}

int compute::get(int x) {
    return a = x;
}

int main() {
    cout << compute::get(3*4) << '\n';
    cout << compute::get() << '\n';

    return 0;
}