#include <cstdio>

int main()
{
    int a=0,b=0,c=0,n=0;
    long long s=0;

    freopen("koba.in","r",stdin);
    freopen("koba.out","w",stdout);

    scanf("%d%d%d%d",&n,&a,&b,&c);
    a%=10;b%=10;c%=10;
    while (n>2)
    {
        a=(c+a*b)%10;
        b=(a+b*c)%10;
        c=(b+a*c)%10;
        s+=a+b+c;
        n-=3;
    }
    if (n==2)
    {
        a=(c+a*b)%10;
        b=(a+b*c)%10;
        s+=a+b;
    }
    else if (n==1)
        s=s+((c+a*b)%10);

    printf("%lld\n",s);

    return 0;
}