# include <bits/stdc++.h>
using namespace std;
ifstream fi("koba.in");
ofstream fo("koba.out");
int s[int(1e8 + 5)];
int main(void)
{
    int n,m=0;
    fi >> n >> s[1] >> s[2] >> s[3];
    s[1]%=10;s[2]%=10;s[3]%=10;
    s[2]+=s[1];s[3]+=s[2];
    for (m=4;m<=n;++m)
    {
        s[m] = s[m-1] + (s[m-1] + s[m-2] * s[m-3]) % 10;
        if (s[m] == s[3] && s[m-1] == s[2] && s[m-2] == s[1]) break;
    }
    if (m < n) m-=3;
    int p = n / m;
    return fo << p * (s[m]) + s[n - p] << '\n',0;
}