#include using namespace std; //入力が必ず-mod<=a //mod<2^30. struct modint{ //mod変更が不可能. public: long long v; static void setmod(int m){} //飾り. static constexpr long long getmod(){return mod;} modint():v(0){} template modint(T a):v(a){if(v < 0) v += mod;} long long val()const{return v;} modint &operator=(const modint &b) = default; modint &operator+()const{return (*this);} modint operator-()const{return modint(0)-(*this);} modint operator+(const modint b)const{return modint(v)+=b;} modint operator-(const modint b)const{return modint(v)-=b;} modint operator*(const modint b)const{return modint(v)*=b;} modint operator/(const modint b)const{return modint(v)/=b;} modint &operator+=(const modint b){ v += b.v; if(v >= mod) v -= mod; return *this; } modint &operator-=(const modint b){ v -= b.v; if(v < 0) v += mod; return *this; } modint &operator*=(const modint b){v = v*b.v%mod; return *this;} modint &operator/=(modint b){ //b!=0 mod素数が必須. assert(b.v != 0); (*this) *= b.pow(mod-2); return *this; } modint pow(long long n)const{ modint ret = 1,p = v; if(n < 0) p = p.inv(),n = -n; while(n){ if(n&1) ret *= p; p *= p; n >>= 1; } return ret; } modint inv()const{return pow(mod-2);} //素数mod必須. modint &operator++(){*this += 1; return *this;} modint &operator--(){*this -= 1; return *this;} modint operator++(int){modint ret = *this; *this += 1; return ret;} modint operator--(int){modint ret = *this; *this -= 1; return ret;} friend bool operator==(const modint a,const modint b){return a.v==b.v;} friend bool operator!=(const modint a,const modint b){return a.v!=b.v;} friend bool operator<(const modint a,const modint b){return a.v=(const modint a,const modint b){return a.v>=b.v;} friend bool operator>(const modint a,const modint b){return a.v>b.v;} friend ostream &operator<<(ostream &os,const modint a){return os<>(istream &is,modint &a){ //入力はmodをとってくれる. long long x; is >> x; x %= mod; a = modint(x); return is; } }; using mint = modint<998244353>; const long long mod = 998244353; template vector> multima(vector> &A,vector> &B){ assert(A.at(0).size() == B.size() && B.size()); int H = A.size(),W = B.at(0).size(); vector> ret(H,vector(W)); for(int i=0; i vector> Powmat(vector> A,vector> B,long long N){ //return A^N*B ABは行列; //n*n行列A n*1行列Bと想定 O(n^3*logN). assert(A.size() && A.size() == A.at(0).size() && N >= 0); while(N){ if(N&1) B = multima(A,B); A = multima(A,A); N >>= 1; } return B; } int main(){ ios_base::sync_with_stdio(false); cin.tie(nullptr); int n = 1'000'000'0; vector prime(n+1,true); prime.at(0) = false; prime.at(1) = false; for(int i=2; i*i<=n; i++){ if(!prime.at(i)) continue; for(int k=i*i; k<=n; k+=i) prime.at(k) = false; } vector twin,allp = {2}; for(int i=3; i<=n; i+=2){ if(prime.at(i)) allp.push_back(i); if(prime.at(i) && prime.at(i-2) && ((i-2)^2) == i) twin.push_back(i); } int T; cin >> T; while(T--){ int N,M; cin >> N >> M; if(N == 1){ int pos = upper_bound(allp.begin(),allp.end(),M)-allp.begin(); cout << pos << "\n"; continue; } int mul = upper_bound(twin.begin(),twin.end(),M)-twin.begin(); vector> A = { {0,1,1}, {mul,0,1}, {mul,1,0} },B = {{1},{mul},{mul}}; B = Powmat(A,B,N-1); mint answer = B.at(0).at(0)+B.at(1).at(0)+B.at(2).at(0); cout << answer << "\n"; } }