#include <bits/stdc++.h>

using namespace std;

namespace NIM {
    static unsigned int f[32][32]; // must be initialized to -1
    void init() {
        memset(f, -1, sizeof f);
    }
    unsigned int nim_mul(unsigned int x, unsigned int y);
    unsigned int nim_mul_2power(unsigned int x, unsigned int y){
        if (!x || !y) return 1 << (x + y);
        unsigned int &F = f[x][y];
        if (F != -1) return F;
        unsigned int ret = 1, tmp = 1;
        for(int i = 0; i < 6; ++i)
            if ((x ^ y) >> i & 1) tmp *= 1 << (1 << i);
            else if (x >> i & 1) ret = nim_mul(ret, 3 * (1 << ((1 << i) - 1)));
        return F = nim_mul(ret, tmp);
    }

    unsigned int nim_mul(unsigned int x, unsigned int y){
        if (x < 2 || y < 2) return x * y;
        unsigned int ret = 0;
        for(int i = 0; i < 32; ++i)
            if (x >> i & 1)
                for(int j = 0; j < 32; ++j)
                    if (y >> j & 1)
                        ret ^= nim_mul_2power(i, j);
        return ret;
    }
};

unsigned int SA, SB, SC;
unsigned int rng() {
    SA ^= SA << 16;
    SA ^= SA >> 5;
    SA ^= SA << 1;
    unsigned int t = SA;
    SA = SB;
    SB = SC;
    SC ^= t ^ SA;
    return SC;
}

void solve() {
    int T;
    cin >> T >> SA >> SB >> SC;
    unsigned int lastans = 0;
    NIM::init();
    while (T--) {
        unsigned int x = rng() + lastans;
        unsigned int y = rng();
        // cout << x << " " << y << endl;
        lastans = NIM::nim_mul(x, y);
        if (!T) cout << lastans << endl;
    }
}

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int T = 1;
    while (T--) solve();
    return 0;
}