#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")

////////////////////////////////////////////////////////////////////////////////
template <unsigned M_> struct ModInt {
  static constexpr unsigned M = M_;
  unsigned x;
  constexpr ModInt() : x(0U) {}
  constexpr ModInt(unsigned x_) : x(x_ % M) {}
  constexpr ModInt(unsigned long long x_) : x(x_ % M) {}
  constexpr ModInt(int x_) : x(((x_ %= static_cast<int>(M)) < 0) ? (x_ + static_cast<int>(M)) : x_) {}
  constexpr ModInt(long long x_) : x(((x_ %= static_cast<long long>(M)) < 0) ? (x_ + static_cast<long long>(M)) : x_) {}
  ModInt &operator+=(const ModInt &a) { x = ((x += a.x) >= M) ? (x - M) : x; return *this; }
  ModInt &operator-=(const ModInt &a) { x = ((x -= a.x) >= M) ? (x + M) : x; return *this; }
  ModInt &operator*=(const ModInt &a) { x = (static_cast<unsigned long long>(x) * a.x) % M; return *this; }
  ModInt &operator/=(const ModInt &a) { return (*this *= a.inv()); }
  ModInt pow(long long e) const {
    if (e < 0) return inv().pow(-e);
    ModInt a = *this, b = 1U; for (; e; e >>= 1) { if (e & 1) b *= a; a *= a; } return b;
  }
  ModInt inv() const {
    unsigned a = M, b = x; int y = 0, z = 1;
    for (; b; ) { const unsigned q = a / b; const unsigned c = a - q * b; a = b; b = c; const int w = y - static_cast<int>(q) * z; y = z; z = w; }
    assert(a == 1U); return ModInt(y);
  }
  ModInt operator+() const { return *this; }
  ModInt operator-() const { ModInt a; a.x = x ? (M - x) : 0U; return a; }
  ModInt operator+(const ModInt &a) const { return (ModInt(*this) += a); }
  ModInt operator-(const ModInt &a) const { return (ModInt(*this) -= a); }
  ModInt operator*(const ModInt &a) const { return (ModInt(*this) *= a); }
  ModInt operator/(const ModInt &a) const { return (ModInt(*this) /= a); }
  template <class T> friend ModInt operator+(T a, const ModInt &b) { return (ModInt(a) += b); }
  template <class T> friend ModInt operator-(T a, const ModInt &b) { return (ModInt(a) -= b); }
  template <class T> friend ModInt operator*(T a, const ModInt &b) { return (ModInt(a) *= b); }
  template <class T> friend ModInt operator/(T a, const ModInt &b) { return (ModInt(a) /= b); }
  explicit operator bool() const { return x; }
  bool operator==(const ModInt &a) const { return (x == a.x); }
  bool operator!=(const ModInt &a) const { return (x != a.x); }
  friend std::ostream &operator<<(std::ostream &os, const ModInt &a) { return os << a.x; }
};
////////////////////////////////////////////////////////////////////////////////

constexpr unsigned MO = 998244353;
using Mint = ModInt<MO>;


void exper(int A, int B, int C) {
  constexpr int E = 20;
  constexpr int N = 160;
  vector<unsigned> X(N);
  X[0] = A;
  X[1] = B;
  for (int i = 2; i < N; ++i) X[i] = (X[i - 1] ^ X[i - 2]) + C;
  for (int e = 0; e < E; ++e) {
    for (int i = 0; i < N; ++i) printf("%u", X[i] >> e & 1);
    puts("");
  }
  puts("");
  for (int e = 0; e < E; ++e) {
    const int mask = (1 << e) - 1;
    for (int i = 2; i < N; ++i) printf("%u", (((X[i - 1] ^ X[i - 2]) & mask) + (C & mask)) >> e & 1);
    puts("");
  }
  puts("");
}

/*
  x[e][i]: e-th bit
  y[e][i]: carry to x[e][i+2]
  
  x[e][0] = A[e]
  x[e][1] = B[e]
  x[e][i+2] + 2 y[e+1][i] = (x[e][i] XOR x[e][i+1]) + C[e] + y[e][i]
  
  over F_2
    x[e](q) = A[e] + B[e] q + (q+q^2) x[e](q) + C[e] q^2/(1+q) + y[e](q) q^2
    x[e](q) = A[e] 1/(1+q+q^2) + B[e] q/(1+q+q^2) + C[e] q^2/(1+q^3) + y[e](q) q^2/(1+q+q^2)
    y[e+1][i] = C[e] (x[e][i] XOR x[e][i+1]) + C[e] y[e][i] + (x[e][i] + x[e][i+1]) y[e][i]
    y[e] -> y[e+1]: divide by (1+q+q^2), pointwise product
    basis: \alpha^i binom(i,k)  (\alpha in F_4,  0 <= k < 2^e)
    denominator 1/(1+q^3)^(2^e)
    x[e], y[e] have period 3 2^(e-1)
    
    after A[e] = B[e] = C[e] = 0
      x[e](q) = y[e](q) q^2/(1+q+q^2)
        q^2/(1+q+q^2) = 001(101)*
      y[e+1][i] = (x[e][i] + x[e][i+1]) y[e][i]
*/

// constexpr int E = 11;
constexpr int E = 21;

int main() {
  // exper(1, 2, 3);
  // exper(123, 456, 789);
  
  int A, B, C;
  Int N;
  for (; ~scanf("%d%d%d%lld", &A, &B, &C, &N); ) {
    --N;
    
    const int mask = (1 << E) - 1;
    vector<int> xs((3 << E) + 2);
    xs[0] = A;
    xs[1] = B;
    for (int i = 0; i < 3 << E; ++i) xs[i + 2] = ((xs[i] ^ xs[i + 1]) + C) & mask;
    Mint ans = xs[N % (3 << E)];
    
    // { y[e][i] = 1 | 0 <= i < 3 2^e && 0 <= i < N }
    vector<Int> is;
    for (int i = 0; i < 3 << E && i < N; ++i) if (((xs[i] ^ xs[i + 1]) + C) >> E) is.push_back(i);
    Int per = 3 << E;
    Mint two = 1 << E;
    for (; is.size(); ) {
// cerr<<"per = "<<per<<", is = "<<is<<endl;
      int x = 0;
      for (const Int i : is) {
        if ((N - i) % 3 != 1) {
          x ^= ((N - i - 1) / per + 1) & 1;
        }
      }
      ans += two * x;
      vector<Int> iis;
      int now[3] = {};
      for (int h = 0; h < 2; ++h) {
        for (const Int i : is) if (h * per + i < N) {
          if (now[i % 3] ^ now[(i + 1) % 3]) iis.push_back(h * per + i);
          now[i % 3] ^= 1;
          now[(i + 2) % 3] ^= 1;
        }
      }
      chmin(per *= 2, N + 1);
      two *= 2;
      is.swap(iis);
    }
    
    printf("%u\n", ans.x);
  }
  return 0;
}