#include using namespace std; //https://trap.jp/post/1444/ constexpr uint32_t totient(uint32_t x){ uint32_t ans = x; for(uint32_t i = 2; i * i <= x; i++) if(x % i == 0){ ans /= i; ans *= i - 1; do x /= i; while(x % i == 0); } if(x != 1){ ans /= x; ans *= x - 1; } return ans; } template struct Modint{ static_assert(P < 0x80000000, "P must be smaller than 2^31"); uint32_t a; Modint b; private: static uint32_t mod(uint64_t x){ if(x < P * 2) return uint32_t(x); return uint32_t(x % P) + P; } static uint32_t mul(uint32_t a, uint32_t b){ return mod(uint64_t(a) * b); } static uint32_t pow(uint32_t a, uint32_t b){ uint32_t ans = 1; while(b){ if(b & 1) ans = mul(ans, a); a = mul(a, a); b >>= 1; } return ans; } public: Modint(uint64_t x): a(mod(x)), b(x){} Modint(uint32_t a, Modint b): a(a), b(b){} uint32_t val() const { if(a < P) return a; return a - P; } Modint& operator*=(const Modint& other){ a = mul(a, other.a); b *= other.b; return *this; } Modint operator*(const Modint& other) const { return Modint(*this) *= other; } Modint& operator+=(const Modint& other){ a += other.a; if(a >= P * 2) a -= P; if(a >= P * 2) a -= P; b += other.b; return *this; } Modint operator+(const Modint& other) const { return Modint(*this) += other; } Modint pow(const Modint& other) const { return {pow(a, other.b.a), b.pow(other.b)}; } bool operator==(const Modint& other) const { return a == other.a && b == other.b; } }; template<> struct Modint<1>{ uint32_t a; Modint(uint64_t x): a(bool(x)){} uint32_t val() const { return 0; } Modint& operator*=(const Modint& other){ a &= other.a; return *this; } Modint operator*(const Modint& other) const { return Modint(*this) *= other; } Modint& operator+=(const Modint& other){ a |= other.a; return *this; } Modint operator+(const Modint& other) const { return Modint(*this) += other; } Modint pow(const Modint& other) const { return {a || !other.a}; } bool operator==(const Modint& other) const { return a == other.a; } }; int main(){ long long M; cin >> M; long long D; cin >> D; long long N; cin >> N; int B; cin >> B; assert(3960 % B == 0); Modint<3960> m(M), d(D); vector> C; C.push_back(m); int t1, t2; while (true){ m = (m + d).pow(m); int cnt = C.size(); bool ok = false; for (int i = 0; i < cnt; i++){ if (C[i] == m){ t1 = i; t2 = C.size(); ok = true; } } C.push_back(m); if (ok){ break; } } int ans; if (N <= t2){ ans = C[N].val() % B; } else { ans = C[(N - t1) % (t2 - t1) + t1].val() % B; } if (ans < 10){ cout << ans << endl; } else { cout << 'A' << endl; } }