int main()
{
    int n;
    scanf("%d", &n);
    d[0] = 5;
    d[1] = 20;
    d[2] = 12;
    d[3] = 2;
    d[4] = 1;
    d[5] = 4;
    d[6] = 6;
    d[7] = 1;
    d[8] = 4;
    d[9] = 4;
    d[10] = 1;
    d[11] = 0;
    printf("%d", d[n]);
    return 0;
}

Yeah, I solved it without looking into discussions.

int n, p[]={5,20,12,2,1,4,6,1,4,4,1,0};

int main()
    {
    cin >> n;
    cout << p[n];
    return 0;
    }

P.S. this problem is EVIL!  (o_O)

Hey, let others also solve it, don't just post here the solution!

Why Sasha is 2, he didnt visit 1 contest

Thank you for your solution, I didn't want to read these megabytes of letters by myself.

+ + + - - - - - - - - -
+ + + - - - - - - - - -
+ + + - - - - - - - - -
+ + + - - - - - - - - -
+ + + - - - - - - - - -
// Dissolution of Alarm
- + + - - - - - - - - -
- + + + - - - - - - - -
- + + - + - - - - - - -
- + + - - + - - - - - -
- + - - - + - - - - - -
// Next year
- + + - - - + - - - - -
- + + - - - + - - - - -
- + + - - - + - - - - -
- + - - - - + + - - - -
// Lesha gone
- - - - - + + - - - - -
- + - - - + + - - - - -
// Nikita & Fedya gone
- + - - - - - - + + - -
- + - - - - - - + + - -
- + - - - - - - + + - -
- + - - - - - - + + - -
// One more dissolution of team
- + - - - - - - - - + + // UNCOUNT
- + - + - - - - - - + -