Pufi i Stojce

//2 ez
#include <iostream>

int main() {
    int z, c, s;
    std::cin >> z >> c >>s;

    int blah = z + c + s;
    int bleh = blah;

    while (bleh % 3 != 0) {
        bleh++;
    }

    std::cout << bleh - blah;

    return 0;
}