#include 
using namespace std;

int main() {
    int a, b, c;
    cin >> a;
    cin >> b;
    cin >> c;
    
    int zbir = a + b + c;
    int ostatok = zbir % 3;
    if(ostatok == 0) {
        cout << 0 << endl;
    }
    else {
        cout << 3 - ostatok << endl;
    }
    return 0;
}